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Users Manual - NASA Infrared Telescope Facility

1. 15 Example Setup for HI Br y 2 16609 um 17 B Observing at th Telescope ororena i occ Saa a ct 17 General Observing Procedures asssssssssssssssssssssssssssss 18 CSHELL Observing Checklist osisssa ccc cece cece ence a n e Sa 19 Flat Field and Dark Frames 00 ce cee ceec cece aaia a a a iai 20 Astronomical Observations cee ceeeeeeceece seca ecceeeeeceueceseaeeenseeneees 20 TMA SIN 27 AEE sv cameods stig E E E E cheetah ee cons 20 SPECHOSCOP Yaca n Geet aaa aspa mk pa aap samasaa 21 Command Fil su n Sua puna Spa up Sus cokt bain TEO IE 21 Common VF Quick Look Techniques aaaaasssssssssss 22 HI CSHELL Instrument Reference r rrrrrrrrrssssssssssssssse 23 A CSHELLXUI and VF Software Description and Reference 24 What is the IC and XUI L u usaq nas a aaa R A ETa 25 Moving the IC computer between the Summit amp Manoa 35 CSHELL XUI IC Command Reference r sssss s 36 Whats VE gitdens terse ssprennaueg tee Soran Banya ass quq a a T qasa auth aks gaye sak 44 VF Source and Docs from IRTF online rrssrsssssissssss 61 VE Command Reference assier aes naq costes EEE RS 64 B Turning CSHELL and its CCD Camera On and OlTf
2. 71 A CSBBIGL Startups Aree a eE E A G E E E 71 B CSHELE Sh tdo WN 2 suaqqa ah E EOE RR TA 71 C CCD Guider Camera usu nupus E at sia ha usss 71 8 16 94 Page 3 IRTF CSHELL User s Guide C Observing Techniques eeri esia eE E A A AEn RERE aT 72 1 Setting IR Array Bias Voltages ccc cece ec eeec cece ance eeeeeeaeeeaeeeaes 72 2 Check For Read Noise Limit and Saturation 72 3 Flat fielding aasan lege tengeguie oyeeechensdenegte depo tee bees 73 4 Focus And Collimation a u n nat mu N Su u i 73 5 Tweaking the CVF for a Flatter Flat s ssssssssssss 73 6 Darks sain Bie eee es he en ae a es 74 7 AcCquiring ObJ 6tS au a aa 74 Q SUG R Ott OM ings u nce de basen hapas lisas peta scape dedeongedeseacades 74 9 Integrations and Nodding cece eee eeeeeeeeeeeeeeeeesennneeaaaea 75 10 Observing Extended Objects cccccceeeeeeeeeesesensnsneeeeeees 76 Ti Command F11es ipana a ded cece esses Seb se a neae ns qasaqa 76 D Observing Spectral LIMES seccssssccececes crest cent vers astvecats R sua a iv ebonsctensaaceneasd 78 1 Popular Astronomical Line LiSst a eeneceeeceeeeaeeeaeenees 78 2 Night Sky OH Lanes sass sitios costes oes a awaspa iu 79 3 Using Calibration Lamps and cal_lines 80 E IRTE Computer Servicess ted cage toys E EEE E ac
3. 8 16 94 Page 34 IRTF CSHELL User s Guide Moving the IC computer between the Summit amp Manoa Because the PC is used both at the summit and Manoa there are changes in some of the setup file which need to be done to allow it to work properly at each location The manoa host name is cshell manoa The summit host name is cshell This page identifies the changes required This is mostly just a reminder for the IRTF programmer or technical staff Cshell users can ignore this page File bin re a At the bottom of the file the rdate program is called to initialization the date and time at boot time Additional line call programs at boot time to initialize the DIO board and PC 38 to mode friendly with CSHELL Change the comment to use the approriation line For example on the summit it would be Addition startup command added by Tony Denault IRTF Programmer usr local bin rdate herschel usr local bin rdate wirth These lines initializes the DIO48 board It set the mode to 0x82 output input output and write 0 s to ports A C usr local bin pc38io o 643 d 130 usr local bin pc38io o 640 d 0 usr local bin pc38io o 642 d 0 This line initialize the PC 38 to power automatic mode usr local bin pc38io rs arpa aspa atpa aupa avpa axpa aypa File net rce network a Insure the host name is correct nsfpc is used on the summit irlabpc is the manoa hostname Look for the following lines and comm
4. Prompt N A Range 0 to 255 for x y wid and hgt 0 to 4 for dframe Initial 0 0 1 1 Syntax StatsObjBox x y wid hgt dframe StatsSetSky This command sets the SkyBox position and skze to be equal to the ObjectBox Prompt N A Range N A Initial N A Syntax StatsSetSky StatsXORLine Set the XOR line postion on the image canvas Prompt N A X and Y must be from 0 to 255 0 0 to 1 1 StatsXORLIne x1 y1 x2 y2 Range Initial Syntax TCSHostname Identifies the host used to handle communications to the TCS TCSHostname on the Setup Frame Range Enter a valid hostname Initial N A TCSHostname host Prompt Syntax UseHex The pixel values are display on the upper right corner of the canvas on Image display mode These values can be based in decimal or Hexadecimal Prompt None Type command a command prompt Range Off Show values as decimal ON Show values as Hexadecimal Initial Off Syntax USEHEX off on Write Writes the content of a buffer to a fits file in the current Path Specifying a filename is optional If a filename is not specified the program will the name assigned with the data Prompt P Range N A Initial N A Syntax write buf filename XCutAutoScale Sets the autoscale flag of the XLineCut graph AutoScale on the main panel for XLineCut display OFF Use Range for scale ON Autoscale the range based on data Initial Off Prompt Range 8 16 94 Page 69
5. lines are left in place from the echellc I project NICMOS amp SBRC 64 control T O Base 0x280 Interrupts None The 8255 1 connected to JO is initilaized using Mode 0x82 Port A Output Port B Input PBO Lamp_limit_off PB1 Lamp_limit_on PB2 vccd_limit_off PB3 vecd_limit_on PB4 dimirror_limit_off PBS dimirror_limit_off Port C Output PCO Lamp_mirror_cntl PC1 vccd_cntl PC2 dimirror_cntl PC3 UNUSED PC4 AR Lamp PC5 KY Lamp PC6 Xe Lamp PC7 Cont Lamp Note currently the DIO48 is onlu used on control the Lamps The additional definition are specified incase we switch the DC motor control from the PC 38 IO bits to the DIO48 SVGA Board CSHELL uses the SVGA board as a text only output device Any generic VGA board will do 8 16 94 Page 100 IRTF CSHELL User s Guide C Troubleshooting CSHELL is a mighty instrument but is not immune to failure We have attempted to identify common possible failures and here we list their modes and possible fixes Always get help from your support scientist telescope operator or other IRTF staff person We now examine some possible failures and their fixes Mojo Motor Madness Each CSHELL mechanism is controlled by a stepper motor or other actuator Sometimes these motors their mechanisms or their electronics fail in various ways Sometimes a mechanism will never become READY at startup of the cshellic software it will stay in the INIT
6. photons Its performance and operating parameters in CSHELL are tabulated below See also Appendix F for linearity data Table 3 CSHELL SBRC 256 x 256 InSb Array Performance Read Noise 55 electrons 1 sample 22 electrons 6 samples Fowler MCS Electrons ADU 11 0 Background Limit 100 ADU in 240 s exposure 6 samples Int Time 76 ms Fowler sampling 50 ms Fast Mode Temperature 30 K Dark Current 0 5 electrons second Quantum Efficiency 80 for 1 um lt lt 3 um 60 for 3 um lt lt 5 5 um Pixel size 30 um 1 linear Well Size 55 000 e 325 mV bias 92 400 e 500 mV bias 170 000 800 mV bias 234 000 e 1 0 V bias see II C IV F Device Artifacts 1000 icky pixels high dark current tachyons re Fowler 8 16 94 Page 10 IRTF CSHELL User s Guide Echelle S Spherical relay mirror Secondary er isa gt _ J TOT 2 lt Flat 4 Collimator primary Slit wheel Flat 3 Filter wheel 2 k amp SA See ae Filter wheel 1 lt Input lens ee Flat 2 Fi Dewar window IR detector array f f _ Q lt Flat 1 Figure 1 CSHELL optical layout The CCD is mounted behind the dichroic but is not shown 8 16 94 Page 11 IRTF CSHELL User s Guide uAous JOU Sqr sse sIaqiy Aq poywoddns Ajreorueyoowu pue poye Ost AT PULIOY st xoq POO Jouur L WD YO SI WONOq 0 W07 se
7. Prompt Range Range 2431 to 2431 1 Initial 0 to 65000 Syntax ImageRange min max ImageScale For the Active Canvas it set the autoscaling on or off When autoscale is on the ImageRange is automatically adjusted to the minimum and maximum values of the data displaying in the canvas This adjustment occures whenever new the data in the buffer changes Prompt Scale on the main panel for Image display Range A autoscale or F fixed scale Initial F Syntax ImageScale A F 8 16 94 Page 65 IRTF CSHELL User s Guide ImageShowScale For the Active Canvas it indicates whether to display an arcsecond scale along side the image display Prompt ShowScale on the main panel for Image display OFF or ON OFF ImageShowScale off on Range Initial Syntax ImageZoom For the Acitve Canvas it sets the zoom factor for an image display This value determines the number of screen pixels each array pixel occupies For example a value of 4 will draw each array pixel on a 4x4 area in the canvas Prompt zoom on the main panel for Image display Range 1 to 20 Initial4 Syntax ImageZoom num LineCutArea Set the range of pixels to be include in NoiseArea Sets the range of pixels to be included in the Noise Display Prompt Area on the main panel Noise display Range All Include all the pixel in the image Box Select the pixels in the object box Initial All Syntax NOISEAREA All Box gt
8. R 2 bl R 1 bl R 0 bl Q P 1 P 2 P 3 P 4 v v 5 3 5 3 5 3 5 3 5 3 5 3 5 3 5 3 6 4 5 3 6 4 6 4 6 4 8 6 8 6 8 6 8 6 8 6 8 6 8 6 9 7 9 7 9 7 9 7 9 7 9 7 9 7 9 7 Intensity 2021 5 6461 6 3466 8 1366 0 3839 3 1217 0 2706 9 1649 0 1917 2 1917 2 5821 0 1031 6 1638 8 620 8 2162 8 1019 6 2710 5 811 3 853 5 883 2 1044 0 2201 2 1533 7 1550 6 1461 3 1081 7 8 16 94 Page 79 IRTF CSHELL User s Guide 3 Using Calibration Lamps and cal_lines CSHELL has three discharge lamps Argon Krypton and Xenon The Xenon lamp is mounted behind one of the other lamps so its lines are very faint Therefore the Ar and Kr calibration lamps in CSHELL are most useful for wavelength calibration of spectra The following table lists their stronger lines s strong and m medium intensity Lamp um Lamp um Lamp um Ar 1 2706m Ar 2 154m Ar2 3 1988m Ar 1 2806m Kr 2 1908s Ar2 3 2882m Ar 1 2960s Ar 2 2083m Ar2 3 3489m Ar 1 3012s Kr 2 2492m Ar2 3 3890s Ar 1 6945s Ar 2 3140s Ar2 3 490m Ar 1 7450m Ar 2 3852s Ar2 3 5839s Ar 1 7920s Ar 2 39738 Kr2 3 6345s Kr 1 8172s Ar 2 5132s Ar3 3 8117m Kr 1 8701m Kr2 2 8861s Ar3 3 8419m Ar 1 9823m Kr2 2 94778 Ar3 4 0112s Kr 2 0215m Ar2 H 3 0101m Ar3 4 0524s Ar 2 0323m Ar2 3 0354m Ar3 4 0879s Ar 2 0622s Kr2 3 0488s Ar2 4 6279s Ar 2 0992s Kr2 3 0678s Kr2 4 6694m Kr 2 1171s Ar2 3 1808m Ar2 4 7703s Beware that the discharge tube quar
9. src DARK mean FLAT FLAT where DARK is buffer 5 and FLAT is buffer 6 Prompt N A Range b must be gereral buffer bO to b4 Initial N A DarkFlat b to b DF Note the DF flags are specified to prevent processing Syntax DisplayType Determines what is display in the active canvas Prompt Display on main window Range Image SA Spectra A Graph SB Spectra B Graph H Fits Header G histoGram L Line cut x XLineCut N Noise Image Initial Syntax DisplayType 11 SAISBIHIGILIX DivByCoadd Enables disables the divide by coadd option Enabling the option cauxe the representation of 8 16 94 Page 64 IRTF CSHELL User s Guide the data to be divide by the number of coadds in the the data frame DFrame DivByCoadd on the Math sub window Range OFF or ON Initial OFF DivByCoadd OFF ON Prompt Syntax DoFile Execute command from a file The subwindow CommandFile allows selection and execution of a macro file Range N A Initial N A Syntax Prompt DoFile filename DoFileMask Set the filemask variable for the filelist showing in the Execute Command File and Edit Command File Frames Filemask on the Execute Command File Frame Prompt Range Any string Initial Syntax DoFileMask string DoPath The Dopath identifies the subdirectory where you will read and wirte command or macro files The filelist on the Execute Command File and Edit Command file Frames is bui
10. NoiseAutoScale Sets the autoscale option of the noise graph Prompt AutoScale on the mail panel Noise display Range off on Initial Off Syntax NOISEAUTOSCALE off on NoiseMod Sets the modual value for the noise display This value control how the columns are grouped together P t Mod on th il I s Noi isplay ie lina Cut Graph es eel e mail panel s Noise display Prompt Area on the main panel for LineCut display mas gt Initial 4 Range All The entire array is used urs SYNTAX Box The subarray defined by the object box ee is used Initial All NoiseG1Range Sets the range of the Y axis for the Max Min M Noi h Syntax LineCutArea All Box Qu ia Meise Gree Prompt Graph1Range on the main panel s Noise I i display LineCutScale Turns the automatic autoscaling Range 2131 to 2434 1 feature off or on for line cut graphs Surt NOISEGIRANGE mi Prompt AutoScale on the main panel for LineCut ae aes display Range Off or On Initial Off NoiseG2Range Sets the range of the Y axis for the t iation Noi h Syntax LineCutScale off on standard deviatom Noise Arap Prompt Graph2Range on the main panel s Noise I Paz display LineCutXY For the Active Canvas it determines the Range 2 31 to 2431 1 and Y axis for a line cut graph A NOISECGBRANGE Mi Prompt X Axis and Y Axis on the main panel for vee MSASA LineCut display f Range X and Y mustbe from 0 to 255 Path T
11. Optics f 13 67 beam at the slit Collimator type Off axis cassegrain Collimated beam diameter 8 0 cm Material Zerodur Grating Milton Roy 31 6 lines mm echelle 63 5 blaze angle Object acquisition capability Visible CCD and direct IR imaging of the focal plane Cooling method Closed cycle cooler with Nitrogen regulation Overall dimensions Inner cold box 56 cm x 19 cm x 18 cm Outer vacuum case 64 cm x 35 cm x 27 cm Direct Imaging Mode CSHELL has a direct imaging mode in which a plane mirror substitutes for the grating and provides an image of the 30 field of view on the infrared array This mode is useful for viewing the field in the infrared acquiring sources 8 16 94 Page 7 IRTF CSHELL User s Guide and centering them in the slit Images of the field may be recorded for reference with either narrow band or standard photometric filters though the system is not meant to provide high quality photometric images Calibration Lamps Argon krypton and xenon spectral lamps and a continuum lamp are provided for wavelength calibration and flat fields Software On line quick look data reduction software is available for use with the instrument It allows examination of the data by providing sky subtraction flat fielding and simple spectral extraction Raw or reduced FITS format data files are recorded in tar format on 4 mm or 8 mm tape Predicted Sensitivity The spectrograph sensitivity F in W m2 um is given by pa
12. Quit XUI software 4 Leave in this configuration unless powering off proceed further only if powering off 5 Turn off the CSHELL Array Power Supplies 6 Type die and lt CR gt in CSHELL IC window Halt Lynx by logging in as shutdown login as reboot if you only want to reboot the IC computer 7 Turn off boxes 2 5 in reverse numerical order C Guider Software Startup 1 Follow Steps AO A3 2 Select Login to CASSPC Guider PC from CSHELL menu 3 Type gic and lt CR gt in the casspc window 4 Select Guider XUI from CSHELL menu Shutdown 1 Quit Guider XUI 2 Type die and lt CR gt in GIC casspc window exit window 8 16 94 Page 106 IRTF CSHELL User s Guide F IR Array Linearity Data 14 April 1994 lab data CSHELL SBRC InSb SCA 052 Science Grade Array Vdduc 3 7 VGG 1 5 1 0 switched off between rows V3 2 9 11 0 e ADU VDET 3 4 BIAS 300 mV t sec ADU e 0 1 231 6 86 5 2539 55 Bias 300 mV 0 25 575 8 96 4 6313 77 0 5 1144 99 8 12538 7 0 75 1706 100 6 18706 7 1 2263 100 8 24808 8 1 25 2811 100 6 30823 2 1 5 3346 100 1 36689 6 1 75 3863 99 3 42358 6 2 4343 97 8 47622 2 25 4737 95 0 51942 3 2 5 5004 90 4 54870 3 5256 79 2 57633 2 5 5238 47 5 57435 8 slope 2196 ADU s offset 48 03 r 1 Charge Dump 178 mV VDET 3 38 BIAS 325 mV 325 mV Linearity t sec ADU e 0 1 224 7 83 7 2463 89 0 25 559 5 95 3 6135 04 0 5 1114 99 6 12209 8 0 75 1659 100 6 18193 5 1 2203 101 1
13. Start VF At this point you should also start VF Access the workspace menu under the CShell select the VF menu item VF should start up immediately Shutting down the XUI amp IC 1 To quit the XUI program by selecting the Quit button on the cshellxui window 2 Backup your data every night with the 8 mm Exabyte tape drive to prevent data loss in case of a disk failure Stop here Normally quitting the XUI is enough The T O or day crew can terminate the IC program The remaining steps will terminate the IC program 3 Enter the die command on the IC computer This will terminate the IC program The message CSHELL is down message is display when all programs are terminated The CSHELLXUI Main Menu The Main Menu provides you access to the command frames and other functions Figure 5 illustrates the menu s selections and give a brief summary of its purpose 8 16 94 Page 27 IRTF CSHELL User s Guide Parameters Gos Options stop Quit Geo Dark Ge Flat Go Comp Save Go obs D Execute DO Files Figure 5 Main Menu Parameters The select button selects the Change item The menu button bring up the sub menu Change Brings up the Parameters window which allow you to view and change the many CSHELL observing Setup and Engineering parameters Save Brings up the Save Parameters as a Macro File dialog window This window allows you to write the current setup
14. Syntax Slice bitslice do_simulate Set the simulation on the DSP Syntax simulate Off On do_status do_stopQ Stop the latest integration Syntax stop do_tcs Send a string to the TCS computer This string is assumed to be a correct TCS Command w 40 chars max This command uses the GO task to communication with the TCS Thus the GO task must be ready before continuing Syntax tcs command string do_tcshostname the host providing the data socket port Sytnax tcshostname hostname do_viewicdata Sets the viewicdata mode for the IC program Syntax viewicdata Off On do_wait Sets the acq task busy for N seconds Syntax wait seconds do_xuihostname the host providing the data socket port Syntax xuihostname hostname 8 16 94 Page 89 IRTF CSHELL User s Guide IV Appendices A Observing Log Sheet and Line Settup Form 8 16 94 Page 90 suvu sseuny ansodxq JoquinN OUIBN AA JoquUINN Jed EA red Ln LAAHSDOT TIAHSI SISATISQO CSHELL Line Setup Form Line Name ___ _ _ Kecaman um Order Og Ng Filt Pos Lamp v em um Kops um Order Other Lines Line telluric object or sky um colops Dispersion um pixel Acvyr um Comments Colored colops km sec pixel IRTF CSHELL User s Guide B CSHELL Hardware Reference 8 16 94 Page 93
15. flat field and dark frame observations All flat field and data frames should be taken without moving the grating or CVF between exposures The next step is to find the array column which corresponds to the location of the slit Do this by acquiring a direct image of the slit insert the direct imaging mirror selecting imaging mode into the light path You may illuminate the sit with either they sky or a discharge lamp Record the array column which the slit is centered on you must position your objects on this column to observe them with the spectrometer This is a good time to enter the slit position the plate scale and slit rotation angle into the TCS Coordinates frame of the VF program Options menu item VF will use this information to calculate position offsets to move the telescope so that your objects fall on the slit Imaging Bright objects K lt 9 are easily imaged in single exposures of 1 second or less Fainter objects require longer exposures and are best observed in a nodding mode in order to subtract the sky background Be sure to check the focus several times a night by imaging non saturated objects at different focus positions using either a FWHM or peak pixel focus evaluation criterion Evaluate 8 16 94 Page 20 IRTF CSHELL User s Guide several exposures or coadds at each focus position to integrate over seeing effects You should be able to achieve a 1 or better FWHM source profile on nights of good seeing Yo
16. which has been artificially extended along the slit direction but it is best to rotate the images first so that the slit is exactly perpindicular to the dispersion axis Additional background subtraction can be done with BACKGROUND IRAF noao twodspec longslit task and then you should register all frames by moving them along the slit direction IDENTIFY IRAF noao twodspec longslit task will allow you to measure the centroid of flux peaks interactively and IMSHIFT IRAF images task allows you to shift the images to a common center Combine all shifted images with IMCOMBINE IRAF images task What you do from here depends on what you want to get out of the data as well as its morphology 8 16 94 Page 87 IRTF CSHELL User s Guide G Using the CSHELL CCD Guider Camera The CSHELL CCD is now a scientific grade Tektronix 512 x 512 pixel CCD which is operated via IC and XUI programs like other IRTF instruments Its startup and shutdown instructions are given in III B It can be operated in a continuous mode for acquisition a single exposure mode or an auto guide mode The CCD is clocked at a rate of 333 000 pixels sec so it takes just under 1 second to read a frame this limits the minimum exposure time also The CCD views the same field as the IR array and is not obstructed by the slit or other apertures It looks through an IR reflecting dichroic which has a pass band similar to an R band filter A 1000x attenuation filter can be s
17. 001 National Solar Observatory as part of the wavelength calibration procedure These atlases are useful for evaluating the strengths and locations of any telluric absorption lines in the wavelength ranges which you will observe This will show you if any telluric lines will land on or near your astronomical ones and these lines may also be used as accurate wavelength references for interpretation of your data while observing You may also observe the sky at twilight to see if the telluric lines occur in their predicted places in your spectra Finally OH sky emission lines can be also used as a wavelength check See III D Example Setup for HI Br y 2 16609 um Suppose that you want to observe the HI Bry line at the 2 16609 um wavelength given as an example in III D First select CVF Open from the Filter icon menu then type this wavelength into the Wavelen text field of the cshellxui Observing Parameters Frame The grating is automatically positioned to the correct angle for observation and the CVF is moved to the selected wavelength Next choose the slit size you wish to observe with and make sure that the grating is selected e g direct imaging mirror is out of the optical path and the shutter is open Note that the Kr lamp has strong lines that are predicted to land at columns 50 95 and 212 of the array see Cal_lines Table in HI D Each of these lines must be observed to adequately measure the dispersion at the 2 16609 um wavele
18. 100 2 139467 1 5 15053 99 2 165059 1 75 17289 98 0 189578 2 19369 96 3 212385 2 25 20884 92 4 228998 3 23580 78 5 258560 slope 9911 ADU s offset 300 9 r 1 VDET 2 7 F BIAS 1000 mV 1000 mV Linearity t sec ADU e 0 1 1217 112 1 13344 7 0 5 5907 112 4 64771 6 1 11245 110 1 123304 1 5 16260 107 2 178294 1 75 18678 105 9 204808 2 20667 102 7 226618 2 25 21902 96 9 240160 2 5 22973 91 6 251904 5 25866 51 9 283626 slope 10861 ADU s offset 0 r 0 995 8 16 94 Page 109
19. 120 sec At 4 8 um np 1000 electrons sec and t 10 sec usually short enough for good sky subtraction We sum 5 pixels in the dispersion direction by 5 pixels 1 in the spatial direction Sensitivities with SBRC 256x256 InSb Array Aum Continuum Mag Line Flux Surface Brightness W m2 um W m resol W m2 sq arcsec 1 25 9 6 x 10 15 13 8 5 6 x 10 19 7 9 x 10 19 1 65 5 6 x 10 15 13 3 4 3 x 10 19 6 1 x 10 19 2 2 3 2 x 10 15 12 8 3 2 x 10 19 4 6 x 10 19 3 4 3 2 x 10 15 10 9 5 1x 10 19 7 2 x 10 19 4 8 8 2 x 10 15 8 5 1 8 x 10 18 2 6 x 10 18 NOTE The above estimates do not account for observing overhead Be sure to allow for acquiring objects guiding inefficiencies changing wavelengths rotating the slit observing the sky you can not nod extended objects within the slit so use the above Surface Brightness numbers and calibrations e g flats lamp lines and standard stars at each wavelength when estimating the total time required for making a set of observations CHECK IRTF ONLINE FOR UPDATED PERFORMANCE INFORMATION Instrument Design Overview Figures 1 and 2 show the light path through the instrument The incoming beam from the IRTF is f 35 and the beam is converted to f 13 67 by the input lens a plano convex BaF lens The input lens forms an image of the focal plane at the slit while forming an image of the pupil at the secondary mirror of the collimator Alignment with the optical axis of the telescope is achieved
20. 1700 CVF Wavelength FILTERA AF4 Open StepPos 1166 FILTERB BCVF1 1 33 to 2 449 CVF StepPos 4540 SLIT 3 Slit Wheel is 2 0 LMIRROR 0 Lamp Mirror is Out LAMP 0 Lamp is Off SHUTTER 1 Slit Wheel is Open VCCD 0 VCCD is Out ARRAY 0 0 256 256 x y wid hgt of data array SAMPLES 6 Number of Samples SAM _MODE 2 1 SINGLE 2 DOUBLE FRM_RATE 6 In msec Fastmode Off SlowCnt 1 Samples 6 RESET_MS 1000 Idle Resets in msec TEMPO1l 30 00 A T1 InSb Array Temp TEMP02 72 20 A T2 Grating Temp TEMP03 180 00 B T1 CCD Temp TEMP04 71 40 B_T2 ColdBox Temp TPD 14 40 38 81 36 58 26 5 01 49 28 21 1 143 1950 0 O RA 14 40 38 81 Right Ascension 8 16 94 Page 85 IRTF CSHELL User s Guide DEC 36 58 26 5 Declination HA 01 49 28 21 Hour Angle AIRMASS 1 143 Air Mass EPOCH 1950 0 Epoch VDDUC 3 700 Programmable voltage VVDUC VDET 3 375 Programmable voltage VDET END the end 2 Data Reduction Guide with IRAF Examples Point Source Data Reduction Note Data should have been taken in nod mode AB or ABBA object is in both A and B beams and nodding along the slit 1 Flat Fields a combine the flat field images e g IRAF function imcombine with avgsigclip b combine dark images e g IRAF imcombine c flat a b e g IRAF imarith d fix badpixels using the badpixel mask e g use fix cl IRAF script e normalize the flat field pro
21. 17365 39143 CA 2317 1316 2116 151 8 20476 191 6 s gas 1717 23607 32920 29809 26702 Yle The Slit wheel is control from the PC 38 from the t axis Note the slit wheel has multiple Blank and Open positions When selecting a Blank or Open the software will move the wheel to the nearest Blank or Open Wheel Size 56000 Menu Index Description Step Degrees 0 0 5 54698 351 6 1 1 0 48487 311 7 2 1 5 39143 251 6 3 2 0 36035 231 7 4 4 0 45362 291 6 5 Blank 1181 7 6 5 Blank 29809 191 6 6 Open 32920 211 6 6 Open 42254 271 6 6 Open 51587 331 6 7 H 8031 51 6 8 K 11142 71 6 9 L 14254 91 6 10 L 17365 111 6 11 M 20476 131 6 12 0 58 4925 31 7 13 Pattern 26702 171 7 14 Pinhole 23607 151 8 8 16 94 Page 96 IRTF CSHELL User s Guide 4 Blocker E2 1 Initial Blank 3 Blank Shutter Wheel Switch Shaft SBRC Array 1 View is from side in whcih filters are installed Unused Bay 2 Switch engaged at postion 1 Both blank 3 Blank in position 3 is used to blank off instrument 4 Motor shown is direction moved when motor turns shaft clockwise The Shutter wheel is controlled from the PC 38 from the v axis Wheel Size 5000 Menu Index Description Step Degrees 0 Blank 125 9 0 1 Open 1375 99 0 2 2 5 SPF 3875 279 0 8 16 94 Page 97 IRTF CSHELL User s Guide RS 232 Devices To communica
22. 256 InSb arrays Larger biases allow more electrons to be collected before saturation but they also cause increased numbers of high dark current pixels icky pixels and low level non linearities Fortunately the icky pixels mostly disappear when object and sky frames are subtracted Dark frames with exposure times equivalent to flat fields should be taken to subtract these pixels from your flats Linearity problems can be avoided if you expose your fats so that they have similar data counts to your object frames You may coadd many flats to achieve high S N I recommend that you pick one of four following detector bias settings for you observations Observation Bias mV Well VDDUC VDET XUI MACRO Most Spectroscopy 325 5000 3 7 3 375 small Bright Thermal Spectroscopy 500 8400 3 7 3 200 medium Bright or Thermal Imaging 800 15 500 3 7 2 900 large Thermal Imaging with very 1000 21 300 3 7 2 700 huge high backgrounds Notes Well The maximum number of ADU counts 1 ADU 11 0 electrons that can be collected while not departing more than 1 from the linearity relation of the mid well range VDET amp VDDUC are detector biases Volts that can be typed into the SETUP Parameters frame of the CSHELL XUI Application XUI MACRO is the name of a command file that can be executed from the Options menu of the CSHELL XUI application These files automatically set the indicated bias levels There are also some other operational changes resul
23. 5 um spectral region CSHELL originally had both Rockwell 256x256 NICMOS3 HgCdTe and Huhes SBRC 58x62 InSb detector arrays but both have been now replaced with a single Huhes SBRC 256x256 InSb device sensitive from 1 5 5 um The instrument also has a direct imaging mode described below Further technical information on the design and performance can be found in Greene et al 1993 Proc SPIE vol 1946 p 313 and Tokunaga et al 1990 Proc SPIE vol 1235 p 131 The Greene et al 1993 paper must be cited in all publications of CSHELL data CSHELL was constructed with funds from the NSF and NASA Its design and construction was achieved by a team of IRTF and IfA personnel The principal specifications and technical features of CSHELL are summarized below 8 16 94 Page 6 IRTF CSHELL User s Guide Tablel General Specifications Array SBRC InSb 256 spectral by 160 spatial pixels Pixel Size 0 20 arcsec 2 7 km s per pixel at blaze angle Wavelength Range 1 08 5 6 um Free Spectral Range 2 5 x 10 3 Resolving Power R 43000 21500 14300 10800 5400 Slit width arcsec 0 5 1 0 15 20 40 Pixels slit 2S 5 7 5 10 20 R A AX Slit 30 in length Discrete slit widths of 0 5 1 0 1 5 2 0 and 4 0 The 4 slit has been provided to permit spectrophotometry on point sources The slit orientation may be changed by manually rotating the spectrograph with the instrument rotator on the telescope Table 2 Key Technical Features
24. Delay 0 7 H6 Hyperbus Port B Delay 0 Delay 0 H7 Real time No clock int Slow No clock int Slow 8 Clock DRAM Speed DRAM mem DRAM mem g MI M2 OuterSRAMB 64k x 4 64k x 4 1 0 M3 M4 Outer SRAM A 64k x 4 64k x 4 1 1 M5 M6 Inter SRAM 64k x 4 64k x 4 The CSHELL project purchased the following DSP boards Two full boards were initially purchased A B C D 1 Serial NUMBER Use SRAM configuration DRAM configuration 2 1052 Clock 64 K words in all 3 banks 256 Kwords or 1 MBtye 3 1054 Buffer 64 K words in all 3 banks 256 Kwords or 1 MBtye 4 8 16 94 Page 99 IRTF CSHELL User s Guide PC 38 Stepper Motor Controller An Oregon Micro System s PC38 8 board is installed to control the stepper motors for NSFCAM The board is configured as follows A B C D 1 Adapter I O Base DMA Channel IRQ 2 PC 38 0x0320 n a n a J47 Limit sense jumpers J15 Address Select Jumbers z 2 i 0x320 J17 Interrupt and DMA Jumpers 3 3 No Ints J67 User I O Pull up Jumpers 3 3 3 J57 I O Configuration Jumpers 0 3 inputs 8 11 outputs 4 7 inputs DIO48 CSHELL make use the the DIO48 Digital I O board to provide additional I O bits Cshell only utilities programs 1 or the 2 available 8255 for digital I O The timera are not used Note The wire wrap between the timer and some DIO
25. IRTF CSHELL User s Guide AF5 Blank Filter Wheel 1 A 11666 300 10966 282 BF5 Blank Filter Wheel 2 B 11900 BF 4 05 un N 143 5561 BCVF1 2 46 to 4 54 um CVF Figure 1 CSHELL Filter Wheels Inner numbers are degrees outer ones are motor step positions 8 16 94 Page 94 IRTF CSHELL User s Guide The filter wheel are controlled from the PC 38 Filter A is on the r axis Filter B is on the s axis The following tables display the name and position of the filters on Filter A and FilterB Filter B Tot Steps 14000 Name Description Degrees Step Pos Filter A Tot Steps 14000 BFI 2 35 NBF 273 5 10636 1 BE2 4 05 NBE 290 11277 8 Name Description Degrees Step Pos BF3 Unused 306 11900 0 AFI Unused 86 3344 4 BF4 Open 330 12833 3 AF2 He I 1 083 70 2722 2 BRS Blank 0 0 0 AF3 Unused 54 2100 0 BE6 2 5 um SPF 30 1166 7 AF4 Open 30 1166 BCVFI1 1 33 to 2 449 CV 52 2022 2 AF5 Blank 0 0 130 5288 9 AF6 4 1 um SPF 330 12833 3 BCVF2 2 46 to 4 54 CVF 143 5561 1 AF7 2 5 um SPF 300 11666 7 225 8750 0 ACVF1 1 10 to 1 57 CVH 102 3966 BCVF3 4 27 to 5 60 228 8866 7 282 10966 7 25 10033 3 The filter menu selection and the position of wheel A amp B are indicated by this table Menu Index Description Filter A position Filter B position 0 CVF amp Open See C
26. Motors window make sure lamps are on look in holes in cal box check instrument power and cables Program bias voltages with Set Programmable Voltages Setup Check cable connections re route data cables away from stepper motor cables ILC 8 16 94 Page 102 IRTF CSHELL User s Guide CSHELL Grating Equations 1 Grating Step N as a function of angle 0 N 1 056 268 18 634 80 0 26 85632 02 22 steps IR array pixel 2 Wavelength to grating angle um 2 o sin0 gt men n order o groove spacing 31 5195 um cold n 3 Order Calculation n 2 o sin0 nearest integer um Nopt 2 o sinbg 56 416 cold Integer Order closest to Blaze angle Og 63 5 um um 4 Dispersion Ad um pixel C A um 2 tan 0 Verifying CSHELL Throughput CSHELL is measured to have 16 5 total throughput including telescope amp atmosphere at 1 25 2 2 um 2 CVF and 12 throughput at 3 4 1 CVF 4 8 um 2 CVF in spectroscopic mode You can use an Elias standard or the continuum lamp flux as a more convenient check um Elias Std 2 clit 6 5 gr Image sky ADU Spec 10w x20pxl 1 2537 HD 161903 J 7 17 55558 in 2 sec 3864 ADU in 60 sec 2 1698 HD 161903 K 7 02 101 981 in 2 sec 2906 ADU in 60 sec 3 526 HR 8143 L 3 71 40 500 in 0 25 sec 26 400 ADU in 30 sec 4 701 HR 8143 M 3 72 8970 in 0 1 sec 4323 ADU in 10 sec um Max ADU pixel in 5 sec
27. SpectraB display amp panel items SetObjBin Pressing SELECT on this button will cause the begining and ending rows of the Object Box to be entered into the ObjBin parameters To the right of this button are text panel input prompts which displays these values SetSkyBin Pressing SELECT on this button will cause the begining and ending rows of the Object Box to be entered into the SkyBin parameters To the right of this button are text panel input prompts which displays these values Show You may specify the data to be plotted for the SpectraB graph Y AutoScale This switch determines whether to autoscale the Y axis or use the fixed scales for the appropriate graph DiffYRange These values provide the fixed scale of the Y axis for the graph of the Difference DataYRange These values provides the fixed scale of the Y axis for the object and sky graphs Set XScale Selecting the Set XScale button sets the x axis to the begining and ending columns of the object bos Your may also type the pixel value in the prompt to set the range for the X axis Print SpectraB Graph Select this button to print the Spectra B graph The Header display shows the text of the fits header in the canvas The Header panel consists of the following items 8 16 94 Page 51 IRTF CSHELL User s Guide Display Header Buffer bi Starting row 0 column O Figure 9 The Header display amp panel items Starting Row amp
28. User s Guide XUIPath This path identifies the subdirectory the XUI programs uses when reading and writing data file Prompt Range Initial Syntax XUIPath on the Observing Parameter s Obs page Any legal UNIX subdirectory scr1 nsfcam data DDMMM Where DDMMM is the current date For example scr nsfcam data 01jan XUIPATH string Command Describe_command Prompt Range Initial Syntax XUi_PROMPTS describe_parameters N A SYNTAX 8 16 94 Page 43 IRTF CSHELL User s Guide What is VF The VF software is a tool used to View Fits data files A brief description of its capabilities are Manipulate fits images of up to 2048 by 2048 pixels using 32 bits per pixel Provides 8 buffers and 5 canvases for holding and viewing e Provide various mode of display such as imaging histogram line cut plus other specialized modes Allows the user to perform arithmetic operation on the fits data e Provides tools the calculate box photometry and statistics on pixels e Produces postscript files of graphics for hard copy output e Provides the ability for the instrument control software to send commands and data to VF VF runs on a Sun Workstation under Sun s Openwindows software It is an X windows application developed using the XView tool kit by the NASA Infrared Telescope Facility The user interface conforms to the Openlook GUI Specifications Before using VF you should become familiar the
29. an integration or GO cycle the stop command is used to abort the acquisition Prompt Stop button on the XUI s command frame Syntax STOP SubArray Load the size and position of the default subarray These parameters are used when setting the subarray from the XUI s array icon on the Parameter s Observing page These parameter refer to an unrotated image This is an engineering command Prompt SubArray on the Parameter s Engineering Page Range x y wid hgt must be a multiple of 8 Syntax SUBARRAY x y wid hgt TCS Using this command you may send a string to the Telescope Control System TCS This string is assumed to be a correct TCS command with a 40 character maximum limit Range Any legal TCS command Syntax TCS string TCSHostName Identifies the computer host accepting TCS commands Range The current TCS host is planck Initial planck Syntax TCSHOSTNAME name TempCmd Sends a commands to any of CShell s two Temperature Controllers Any string after the TempCmd is send to the temperature controller Please refer to the Description of Hardware section or the temperature controller s manual for the correct syntax for the temperature control commands Range Any legal controller command Syntax TEMPCMD AIB string TempRecord TempRecord allows you to switch OFF ON the recording to temperature information When ON the temperature information is appended to the file temper log The recording inter
30. and travels through it On top of each icon the name of the component is shown On the bottom its current value or setting is shown For example look at the shutter s icon and you can see it is currently open Each icon is colored gray or yellow Yellow shows that an item is in the optical path while gray shows you that an item is either blocked or moved out of the optical path For example if the Filter is set to blank all the icons to the left will be gray since the filter is blocking the light The other prompts and menu are usually self explanatory For a detailed explanation of each options refer to the CSHELL Command Dictionary For example if you wish to know what happens when you change the value for CVFWlen look up CVFWlen in the dictionary A detailed explanation is provided Special Notes 1 Input a wavelength or wave number into the Wavelen parameter to move the grating to the desired wavelength The CVF is also automatically changed to the proper wavelength 2 Coadds is the number of coadds per beam 8 16 94 Page 30 IRTF CSHELL User s Guide 3 Cycles determines the number of times an observing mode is repeated 4 ObsMode determine how many beam switches are done 5 After the Lastframe label you are presented with 3 panel items Buffer Dark Flat These items control how the data is sent to the VF program upon reading out the array In stare observing mode data is sent to the buffer specified In n
31. as a macro file Go The select button select the Go Obs item The menu button brings up the GO sub menu Go Obs Starts an integration creating files with the a or b extensions and IMAGETYP object in the header Go Dark Starts an integration creating files with the dk extension and IMAGETYP dark in the header Go Flat Starts an integration creating files with the fl extension and IMAGETYP flat in the header Go Comp Starts an integration creating files with the cll extension and IMAGETYP object in the header Options The select button selects the Execute Do Files item The menu button brings up the sub menu Execute DO Files Brings up the Edit Command Files window This window provides the ability to create edit save load and execute macro files Stop The stop button will abort the current GO operation Quit The quit button will exit the application The Status Canvas The Status Canvas is used to display the current state and configuration of CSHELL A number of formats are available to you To change the format select an item from the status canvas menu panel item URE Temp Temp Temp B1 10 Temp Status Motors Tempclt About Figure 6 Status Canvas display Status Selecting status from the status canvas menu specifies a format similar to figure 4 This is the default selection The information is grouped in 3 sections labeled STATUS SET UP and TEMPERATURE Under S
32. because of non linearities and icky pixel artifacts in the SBRC 256 x 256 InSb arrays Larger biases allow more electrons to be collected before saturation but they also cause increased numbers of high dark current pixels icky pixels and low level non linearities Fortunately the icky pixels mostly disappear when object and sky frames are subtracted See IHI C 1 and Appendix F for more information on selecting appropriate detector bias voltages Remember to transfer your data to magnetic tapes it is best to do this at the end of each night at Hale Pohaku See III E for details Also remember that telescope operators are allowed to work no more than 12 hours at a time on the summit plan your calibrations observations and data archiving accordingly You may stay to archive data after the operator leaves Be sure to set the CSHELL filter and slit wheels to their Blank positions and terminate the cshellxui software program at the end of each night Ask the operator to shut down the instrument if there is a danger of lightning See II B for details See the following Observing Checklist for more details Next we consider some details of the observing procedure We present a reference of observing techniques in III C 8 16 94 Page 18 IRTF CSHELL User s Guide CSHELL Observing Checklist Before Leaving Home Produce Objects Standards and Guide Stars Lists Calculate Integration Times for Desired Sensitivities Determine Slit Orie
33. by translating and rotating the input lens and flat number 1 together as a unit A dichroic mirror reflects the IR to the slit while permitting the visible light to be viewed with a visible CCD not shown This permits acquisition and guiding on objects with a visible light counterpart The order separating CircularVariable Filter CVF wheels are positioned at a suitable distance from the slit such that the width of the incoming beam is not wider than a single resolution element of theCVF This maintains the spectral purity of the beam through the CVF 8 16 94 Page 9 IRTF CSHELL User s Guide The CVFs were selected from the stock catalog of Optical Coatings Lab Inc These CVFs cause ripples in CSHELL spectra with amplitudes of 10 20 peak to peak and periods of 2 10 cycles per frame due to optical interference in their substrates This is CSHELL s most severe remaining instrumental problem However we have constructed discrete He I 1 083 um and HI Br y 2 167 um filters which do not exhibit this fringing and are also investigating replacing the CVFs with ones that will not exhibit fringing The lt 2 5 um CVFs also have small leaks from adjacent grating orders with maximum leak amplitudes at their shortest wavelenghts 2 at 1 1 um After the filter wheels the beam passes through an off axis Cassegrain collimator designed to produce a collimated beam 8 0 cm in diameter The effective focal length of the collimator is 109 cm and
34. define the Y scale for the standard deviation graph 8 16 94 Page 54 IRTF CSHELL User s Guide The Read Data Frame Selecting Read Data from the File submenu will causes the Read Data command frame to appear on the screen This command frame enables you to read data into the data buffers at Read Data File Path tmp_mntfhomes wirth wirth denault data Filemask jup_obj 5 OSapr jup_sky OBapr O apr o8apr 13apr Buffer 7 bo Load Fits Load Mern Update Lists Hide Figure 13 The Read Data frame There are two lists on this window On the left is the file list which list all the files in the Path matching the Filemask string pattern You may select filename with the mouse to identify the file you wish to read On the right is the directory list The directory list display the name of the directory in the current path Using the mouse you can double click on these name to change the Path The other Panel items inside this command frame are Path This text panel item identifies the subdirectory containing the file you wish to read You may change the Directory by editing this text panel item Filemask This filemask determines which filename from the Directory are displayed in the list panel item Filemask is normally set to a regular expression to allow only those filenames matching the pattern to be included in the list For example fts will allow any filename that ends with
35. fts to be include in the filelist You may change the filemask by editing this panel item Use the cursor to select the file you wish to read Buffer The data will be read into the buffer idenified by this panel item Select the desired buffer from the menu Load Fits Clicking on the Load Fits button will command VF to read in the select FITS image Load Mem Protocam mem files may also be loaded Selecting this button will load the highlighted mem file Update List This button will update the filelist This is necessary because UNIX is a multitasking operating system and a file can be created or deleted or renamed without the knowledge of the VF program Hide Selecting this button will cause the command frame to disappear 8 16 94 Page 55 IRTF CSHELL User s Guide The Save Data fame Selecting Save Data from the File submenu will cause the Save Data command frame to appear on the screen This command frame enables you save or write the data from a buffer to a file Save Data File Status Saved Buffer bo Directory ntfhomes wirth wirth denault data protocam Filename tonydrkfts Save Hide Figure 14 The Save Data frame The Panel items inside this command frame are Buffer This panel menu item identifies the buffer holding the data to be written Select the buffer you wish to save Directory This text panel item identifies the subdirectory containing the file you wish to write to You may
36. may be loaded edited and saved with this window also Commands may be entered into files by either recording your real time manipulations of the spectrometer check Record button in the Commands frame or typing the text commands into the edit window of the Commands frame Command syntax is identical to the cshellxui cshellic and VF command line syntax see III A Cshellxui command files are stored in the macro cshellxui directory of your guest observer account and VF command files are in the macro vf directory These are the default directories that the 8 16 94 Page 21 IRTF CSHELL User s Guide programs use to load and save command files There are more macros in the cshell macro directories and you may copy ones from there to your guest account The most commonly used command files are godark goflat image and spect These commands execute a series of dark exposures a series of flat field exposures set up for a pair of nodded images and set up for a pair of nodded spectra respectively Command files starting with go e g godark goflat godark have Go Obs as their last commands so exposures are actually taken when they are executed Command file names without go e g image obs do not contain Go Obs statements exposure times or other parameters may be modified before starting exposures if you are using these files The commands in these files are listed in SHI C 11 Command file execution may be usually rep
37. off A and B frames when observing in a nod mode It is in your best interest to guide the telescope using a guide star in the field of either the internal CCD or offset guider camera Guiding is required for good signal to noise ratios The mean of the A B data pairs can be accumulated in a buffer if you are taking many spectra of an object The MeanFrame buffer is initially set to N A to disable this feature To turn it on select an unused buffer from its list in the Observing Parameters Frame This buffer will then contain the mean A B for the current set of cycles Command Files The cshellxui and VF programs can read command files which automatically configure CSHELL This is a great advantage over the manual configuration of each mechanism for commonly used instrument setups For example one can create and execute a command file which selects a detector bias for spectroscopy puts in a slit switches to spectroscopic mode and sets the integrations This is in fact what the spect command does and it can be used to automatically configure CSHELL for spectroscopic observations Likewise image will configure CSHELL for imaging and a VF command file can subtract 2 buffers and divide the result by the Flat Field buffer Command files maybe be created and edited in several ways The current state of all CSHELL mechanisms may be recorded into a command file by selecting the Save Parameters item in the cshellxui Parameters menu Command files
38. swith in seconds Prompt Beamswitch DTime on the observing parameter s Setup page Range 0 to 10 seconds 8 16 94 Page 37 IRTF CSHELL User s Guide Initial 2 Syntax DTIME sec EPassWord The Epassword command allows you to enter a password After entering the password sucessfully any restrictive parameters ie engineering can be modified Issing the command with an invalid password will cause those parameters to be restricted Prompt epassword on the observing parameter s Eng page Range Any string Syntax EPASSWORD string Filename The filename s prefix is used ot create filenames when saving data to disk New filenames are constructed by concatendating Filename with the Image Number then adding a file extension For example if Filename is 01jan and image number is 45 the data file saved could be 01jan045 a Prompt Filename on the observing parameter s Obs frame Range A string of 8 characters Initial The current date in the form DDMMM Syntax FILENAME string Filter Select a filter combination using the 2 filter wheels The selection are indicated by the index values Prompt Click on the Filter Icon on the observing parameters window 0 CVF Wlen amp Open 1 2 35 um NBF amp Open 2 4 05 um NBF amp Open 3 He 1 083 amp Open 4 HI 2 167 amp Open 5 Both wheels blank 6 CVF Wlen amp Open 7 2 35 um NBF amp Blocker 8 4 05 um NBF amp Blocker 9 2 5 um
39. syntax is case senitive The syntax for the command to the IC to sent temperature commands is TEMPCMD A B command Encoder The default encoder parameters are SN 0 SP 0 SE 0 AR 0 SD 0 SO 0 SF 0 8 16 94 Page 98 IRTF CSHELL User s Guide CSHELL s RACKMOUNT SETUP CSHELL Instrument Control computer is a 20 slot 386 20 Rackmount PC AT computer This section attempts to documents the setup the various peripheral board install in the PC Ethernet Card The ethernet card for the PC is a SMC EtherCard Plus Elite16 This is the default card supported by lynxOS We have configured the board to be compatiable with Lynx The board is setup as follows A B C D E 1 Adapter T O Base Addr DMA Channel IRQ Other Notes WD EtherCard Plus Elite 0x240 0x25f N A ROM Based addr None Disabled Shared RAM at CC000 2 5 MM 96 Detailed Setup CSHELL uses two MM 96 DSP to provide clocking and buffer board functions The clock DSP make no use of any DRAM While the BCARD DSP uses the additional DRAM up to 16Mwords in speckle and movie mode A B C 1 Clock DSP Bcard DSP 9 PC I O Address 0x148 NFNFNNEN 0x158 NFNFNFEN DMA No DMA HI amp H2 No DMA HI amp H2 3 Unlinked Unlinked 4 H3 IRQ 11 Connect 7 amp 8 12 Connect 5 amp 6 5 H4 DSPnet Address 0 connect pins 5 amp 6 0 connect pins 5 amp 6 g H5 Hyperbus Port A Delay 0
40. this parameter specifies the wavelenght for the CVF filter Setting the CVFWlen update the user s order which specifies which 8 16 94 Page 36 IRTF CSHELL User s Guide order to be used by grating to observe at the wavelen specified by CVFwlen Prompt CVFWLen on the Filter Wheel Dialog Box Range 1 0 to 2 449 or 2 46 to 5 6 Initial 2 20 Syntax CVFWLEN num Die This command stops the execution of the IC program This command can only be executed from the IC program Syntax DIE DiMirrorlnit The command to initialize the Direct Imaging Mirror The DiMirror places the insturment in spectrscopic or imaging mode Syntax DIMIRRORINIT Display This command selects the various screen layouts on the IC program This command can oly be executed form the IC program Prompt XUi_PROMPTS Range 0 Displays the most common observing parameters 1 Display the descriptive text parameters 2 Display the engineering parameters Initial 0 Syntax DISPLAY num DoFastMode Select the fast or slow clocking mode by setting Fastmode on or off This is an engineering command Prompt DoFastMode on the observing parameter s Eng page Range Off Slow clocking mode On Fast clocking mode Initial Off Syntax DOFASTMODE off on DoFile This command starts exection of a macro file Prompt See Execute Command File in the XUI User s manual Syntax DOFILE filename DoFileMask This command sets the pattern s
41. 1 Print LineCut 32500 Figure 11 The LineCut display amp panel items 8 16 94 Page 52 IRTF CSHELL User s Guide X Axis Identifies the X axis used to draw the line cut Y Axis Identifies the Y axis used to draw the line cut AutoScale This switch determines whether to autoscale the graph or use Range to determine the scale Range These values determine the minimum and maximum values of the scale when autoscale if off Area The area along with the X amp Y Axis variables defines the pixel domain for the graph The options are All and Box When All is selected the entire frame is plotted When Box is selected the Object box is used to define the region to be plotted Print LineCut Select this button to produce a hardcopy of the graph displayed in the canvas The XLinecut displays a single linecut graph between 2 points or pixels The XLinecut panel consist of the following panel items Display Linecut Buffer bl Set Endpoints from line Beg 00 End 128 129 AutoScale off On Range 8920 to 26157 Print xCut Figure 12 The XLineCut display amp panel items Set Endpoints from line SELECT this button to use the coordinates of a line drawn on the image to be entered as the endpoints of the graphs AutoScale This switch determines whether to autoscale the graph or use the range to determine the scale Beg to End These coordinates identify the endpoin
42. 10 steps Be sure however to acquire all data object and flats for each wavelength at the exact same CVF and grating positions do not move the grating or CVF in between data frames unless changing wavelengths 8 16 94 Page 73 IRTF CSHELL User s Guide The CVF position can be seen in the Motors frame of the main cshellxui window The CSHELL command Filterpos can be issued to move the CVF filter wheel a small amount Consult the Hardware Reference Appendix B for the command syntax and to determine which CVF and wheel should be moved 6 Darks Darks should be taken whenever flats are taken and the exposure time should be the same as the flats Dark current is normally subtracted from object data when differencing object and sky frames acquired in Nod mode Flat fields must have their dark current and icky pixels removed during the reduction process by subtracting separate dark frames Darks must be acquired with the same detector bias setting as your object and flat field data Close the shutter before taking dark frames 7 Acquiring Objects To acquire objects first determine the position of the slit on the array that you are using Take an image of the slit in the Direct Imaging Mode looking at the sky or a discharge lamp Kr or Ar You should get an image of the slit with an integration time of a few seconds or less Record the central column of the slit It will change at each cool down of the CSHELL but it is usual
43. 2 Type openwin and lt CR gt at the UNIX prompt 3 Hold down the right mouse button on the blue desktop 4 If the IC program is not already running ASK a T O or Support Astronomer Either 1 Select Start CSHELL IC Software from the CSHELL menu or ii Log into CSHELL IC console as cshellic 5 Select Cshell XUI from the CSHELL menu 6 Select VF from the CSHELL menu 7 Turn on the CSHELL Array Power Supplies left on if cshellic is running 8 Set Programmable Voltages in Setup Parameters XUI Window B CSHELL Shutdown 1 Quit VF 2 Move Shutter Slit and Filter to Blank Position Spectroscopic mode turn lamps off 3 Quit XUI software 4 Leave in this configuration unless powering off proceed further only if powering off 5 Turn off the CSHELL Array Power Supplies 6 Type die and lt CR gt in CSHELL IC window Halt Lynx by logging in as shutdown login as reboot if you only want to reboot the IC computer C CCD Guider Camera Startup 1 Follow Steps AO A3 2 Select Login to CASSPC Guider PC from CSHELL menu 3 Type gic and lt CR gt in the casspc window 4 Select Guider XUI from CSHELL menu Shutdown 1 Quit Guider XUI 2 Type die and lt CR gt in GIC casspc window exit window 3 Power Off Only Login as oroot or sroot and type reboot ah before power off or just type reboot a to reboot only 8 16 94 Page 71 IRTF CSHELL User s Guide C Observing Techniques 1 Setting IR Arr
44. 24156 4 1 5 3266 100 7 35812 4 2 4307 100 1 47227 2 2 25 4807 99 4 52709 8 2 5 5271 98 2 57797 7 3 5987 93 1 65648 8 5 6254 58 6 68576 5 slope 2124 ADU s offset 55 93 r 1 8 16 94 Page 107 IRTF CSHELL User s Guide VDET 3 3 BIAS 400 mV t sec ADU e 400 mV Linearity 0 1 244 6 85 9 2682 09 0 25 607 6 96 0 6662 47 0 5 1209 99 6 13260 2 1 2397 100 9 26283 6 1 5 3566 100 8 39102 2 4705 100 2 51591 4 2 5 5830 99 5 63927 2 3 6923 98 6 75912 2 3 5 7998 97 8 87699 8 5 9565 82 0 104882 10 9450 40 6 103621 slope 2323 ADU s offset 52 43 r 1 VDET 3 2 BIAS 500 mV t sec ADU 500 mV Linearity 0 1 255 3 77 1 2799 42 0 5 1261 97 5 13827 1 1 2501 100 2 27424 1 5 3723 100 7 40823 5 2 4928 100 6 54036 6 25 6107 100 1 66964 6 3 7273 99 6 79750 1 3 5 8421 99 0 92338 1 4 9544 98 3 104652 5 11710 96 7 128403 10 13471 55 8 147712 slope 2405 ADU s offset 90 53 r 1 VDET 3 1 BIAS 600 mV 600 mV Linearity t sec ADU e 0 1 264 6 67 2 2901 4 0 5 1308 95 2 14339 2 1 2593 99 8 28427 3 2 5113 101 3 56065 2 3 7567 101 0 82973 8 4 9943 100 0 109027 5 12252 98 9 134346 6 14469 97 5 158656 7 16507 95 5 181003 15 17590 47 7 192878 slope 2448 ADU s offset 148 8 r 1 8 16 94 Page 108 IRTF CSHELL User s Guide VDET 2 9 BIAS 800 mV 800 mV Linearity t sec ADU e 0 1 1076 83 3 11798 6 0 25 2670 96 1 29277 1 0 5 5280 100 4 57892 0 75 7814 101 0 85682 2 1 10304 100 9 112986 1 25 12719
45. 5 umnopA TEMP OY JO YFU ML TTHHSO JO SMOIA Opts pue OL Z INST aseo uInnopA 1uBil a Buyout xoq ploo Y t uinnoea Jemaq S UA 1891l d d101YIIG cums ese 10349948Q HI SI UA 19 ll4 e eld f lt v ld I UM WIS x eld 40ye WI O9 Ayewid Mewnd JOWUIW Jow Buibeul 1q BuIBeuui paq JOJU Ayepuooes Ages yeoeyds Hulwoou Buisnou AHDp l u53 ll uo3 3119493 JOAId X 3 Retr ie iene iad ao a i a a Jeqqny ANp eg 4 SMO 9 7 lea ullino EEEE E ae ee lt 191009 9 5 p solO 1 oo2 j9 9 p so O N Page 12 8 16 94 IRTF CSHELL User s Guide ll Using CSHELL NOTE This section assumes the user is familiar with the basic function of the cshellxui data acquisition and vf quick look data reduction programs See the cshellxui and vf documentation III A for information on the details of this software Powering up CSHELL and starting its software explained in III B initializes the instrument in a safe state the calibration lamps are off the lamp mirror is out the filters and slit are in closed blank positions and the shutter is closed This is done by the telescope operator day crew or support scientist No light enters the spectrometer or falls on the infrared array in this initialized configuration but the internal CCD can see out through the telescope This configuration is graphically represented by the cshellxu
46. Any string up to 40 characters VDET Then select the Set Programmable Initial Your name Voltages with the mouse to send these values Syntax OBSERVER string Range VDDUC range is 3 75 to 2 505 volts VDET range is 3 75 to 2 505 volts ObsMode The observing mode determines the beam Me switch pattern performed in a GO sequence and when in In addition vdet gt vddue and vdet the sequence the files are saved The obmode is identified vdduc lt 1 5 volts by an index number Initial Undefined You must initialize the voltage as Prompt Obs Mode on the observing parameter s part of your startup procedures Obs page Syntax PVOLTAGE vdduc vdet Range 0 Obj A integrates at the present beam position This data is treated as an object PWindow The PWindow variable indicates which frame parameter page should be displayed in the Observing 1 Sky B integrates at the present beam Parameters frame position This data is treated as a sky Prompt Set of Blue colored button in the upper right frame corner of the Observing Parameter frame 3 Pair AB In this mode a pair of frames Range 1 Obs Displays is most commonly changed are taken First the telescope is position at Observing parameters 8 16 94 Page 40 IRTF CSHELL User s Guide 2 Setup Displays the setup parameters These parameters should be examine at the start of you observing session 3 Eng Displays the engineering parameters These are restricted par
47. Blocker 10 4 1 um Blocker Blank Blank 2 20 FILTER 0111213141516171819110 Range Initial Syntax FilterInit This command will initialize the filter wheels by moving them to their limit switches and then moving them to their initial position Syntax FILTERINIT FllterPos Allows you to position the filter wheels to any step position Normaily you may only offset the wheel position 100 or 100 steps from its normal location After entering the engineering password this restrictions is removed but be careful of flashing the array in this mode 1 to 40000 FILTERPOS A B step AIB step Range Syntax Go Performs a GO which is a set of integrations The GO command can take an optional parameter which determines the type extension for filenames in basic mode Please read the section description of CamModes for a more complete description Syntax GO obs dark flat comp Golnit Initializies the go task in the IC program The go task is responsible for controlling the DSPs and Array s electornics Syntax GOINIT GoReset Places the DSP in a reset operation mode The go task s state will be change to ERROR Syntax GORESET Gratinglnit Initializes the grating The grating is initialized by reading the step position from the encoder to set the step postion of the grating s stepper motor Syntax GRATINGINIT GratingPos Commands the grating s stepper motor to move to a specific st
48. Column Identifies the first character and line to be display in the upper left corner of the canvas It s more convenient to use the scrollbars rather than change these values The Histogram display draws a histogram on the canvas and its panel consist of the following items Display lt histeGram Buffer b1 96 00 of the data is graphed Range 8920 to 26157 2 00 is less than low range Number of bins 1 100 50 0 0 is greater than high range l Aol e Area All Box Print Histogram Figure 10 The Histogram display amp panel items Range These values determine the minimum and maximum values of the X axis of the histogram and will be equal to the ImageRange Changing the histogram range will change the ImageRange and vice versa Num of Bins This is the number of bars on the histogram The size of bin is determined by dividing the range by the number of bins Area These control allow you to indicate the pixel used in creating the histogram You may use the entire image All or just the pixel specified by the ObjBox Box Print Histogram Select this button to produce a hardcopy of the histogram The Linecut display will show a graph of the pixel values along the x and y axes The Linecut panel consist of the following panel items Bleurenus fest s5000 j 47500 ae Display Linecut Buffer b1 X Axis 0 sis Y Axis O sirj Area All Box AutoScale Off On Range 8920 to 26157
49. File frame filename Name of file to read This file must exist in the subdirectory defined by PATH B Any valild buffer for example b0 Initial N A Syntax Read filename B Range ReadMem Reads a ProtoCam mem file from the current path into the buffer Prompt The Load Mem button on the Read Data File frame filename Name of file to read This file must exist in the subdirectory defined by PATH B Any valild buffer for example b0 Initial N A Syntax ReadMem filename buffer Range ReadSock Read a fits file from the current socket connection Prompt N A Range B Any valid buffer for example b0 Initial N A Syntax ReadSock buffer RotateBuf Rotate s the data in a buffer by translating the X and Y axis The buffer can be rotated in the clockwise or counter clockwise direction Prompt Rotate CW amp CCW buttons on the Math frame Range N A Initial N A Syntax RotateBuf B cw ccw SAObjBin Sets the range of rows to be used as the object bin in the Spectra A graph Prompt OBjBin on main panel for SpectraA display Range 0 to 255 Initial O Syntax SAObjBin min max SARowPerBin Sets the number of rows per bin for a Spectra A graph Prompt RowPerBin on the main panel for SpectraA display Range 1 to 255 Initial 10 Syntax SARowPerBin num SAShift Specifies the amount of shift in the x axis to be applied when converting pixel columns to wavelenght Prompt Shift on the ma
50. Fo SiR Nn n t a T t Other parameters are Fo 2 4x10719 lt 3 um 16 5 throughput blaze angle 3 2x10 19 A gt 3 um signal to noise ratio resolving power wavelength in um total number of pixels summed spatial spectral directions including sky electronics noise readout and other sources in electrons dark current and background in electrons sec individual exposure time total observation time 4 B gt Z gt m m Below we present the sensitivity for S 10 R 21500 1 0 slit and T 1 hour Calculations are for a point source in which sky subtraction is achieved by nodding the telescope along the slit such that the object remains in the slit for the surface brightness sensitivity the telescope is nodded to blank sky Pixels are summed 1 along the slit and over one resolution element along the dispersion direction therefore the results are per 8 16 94 Page 8 IRTF CSHELL User s Guide resolution element not per pixel The numbers below may be scaled to other cases using the above formula but longer guided exposures can improve sensitivities We use a system electronics noise of 35 electrons This is representative of almost the entire array including high dark current pixels for 240 s exposures with 6 samples Fowler MCS technique at 325 mV applied bias For wavelengths short of 2 5 um we take Nb 5 electrons sec and t 240 sec At 3 4 um np 28 electrons sec and t
51. IRTF CSHELL User s Guide Syntax XCutAutoScale off on XCutSet This command identifies the endpoints of the line of pixels used to construct the XLineCut graph Prompt Beg and End on the main panel for XLineCut display Range x amp y must be from 0 to 255 Initial N A Syntax XCutSet x1 y1 x2 y2 8 16 94 Page 70 IRTF CSHELL User s Guide B Turning CSHELL and its CCD Camera On and Off The day crew should power on the instrument and run checks Power is left on continuously except for conditions that may lead to abandonment of the summit or lightning The cshellic software is usually left running on the IC computer These procedures are for the Telescope Operators and support scientists Observers should not attempt to power CSHELL on or off All software can be started up from your user account on an IRTF Sun workstation at the summit planck or HP wien Remember to type xuihostname wien in the command line of the CSHELL XUI program if running from that HP workstation The CSHELL and CASSPC the guider pc Instrument control IC Intel architecture computers can also be logged into from their directly connected keyboard monitor consoles The new calibration lamp program is called cal_lines which should be typed in from a UNIX prompt A CSHELL Startup 0 Turn on CSHELL boxes 2 5 in numerical order done at start of run by day crew 1 Log into your Guest Account IRTF staff can use cshell account
52. If you agree with the offset coordinates in the Offset is ra dec prompt press Offset TCS button Pressing this button will sent a command to the TCS to offset its position by the indicated coordinates Note The TCS command issued by VF to perform the offset is 0 ra dec 0 C PEAK 8 16 94 Page 60 IRTF CSHELL User s Guide The Set Up frame The Set Up Parameters frame contains panel items which are not likely to be changed very often The item are usually self explanatory For a detailed explaination of each option refer to the VF Command Dictionary Path scrl1 data Printer irtfpr Printer Type T B amp W Postscript Div by coadd bo b2 b4 BadMask Set Bad Mask b1 b3 TCShostname p Figure 19 The Set Up frame Special Notes To set up a bad pixel mask read in the fits file representing your bad mask into any buffer Pixels with a value of zero are considered good pixels while non zero values represent bad pixels Indicate the buffer holding the bad pixel mask by selecting its buffer index from items to the right of the Set Bad Mask button Selecting the Set Bad Mask will cause VF to scan the buffer and initialize the bad pixel mask Once the bad pixel mask is installed its effects can be turned off or on using the BadMask buttons See the command BadMask for more information VF Source and Docs from IRTF online An anonymous FTP site has be setup at the Institute for Astronomy at the Un
53. Infrared Telescope Facility Institute for Astronomy University of Hawaii 2680 Woodlawn Drive Honolulu HI 96822 CSHELL NASA IRTF Cryogenic Echelle Spectrograph USER S MANUAL Revision 2 0 1 16 August 1994 ey J s T Greene lt A Denault IRTF CSHELL User s Guide Lots of Mahalo to Alan Tokunaga for immeasurable guidance throughout the CSHELL project 8 16 94 Page 2 IRTF CSHELL User s Guide Table of Contents IRTF CSHELL User s Manual I Intron u eesa guste ete een a ae ween deupeeudesaveeadynse heed gested ise EEEE E E ened 5 A Preparations Before Coming to the IRTF r arasrssssssssssssssassass 6 Bz Instrument Deseripttoni qu a u usnu EE E eet teens 6 Tablel General Specifications L 7 Table 2 Key Technical Features ua E a quy 7 Predicted Sensitivity ss sr e tan obi ag teeg aectass dec E A ETO te aaa sawas 8 Instrument Design OVerVIeW iiaei ea eee aS Sau n iia 9 Table 3 CSHELL SBRC 256 x 256 InSb Array Performance 10 JL Using CSHB LD iisceccsccdcssscieccsccasessaesedesnonendasnssgesegeeenbasabsiedegseesminssiessecgceceesmnetesedears 13 A Before Night Time Observing icici cn aina a eee aai iR TET 14 System Checkouts merena e a M a m ru aaa 14 Signal and Noise Checks ss irissiseriersiseesrirnisseisrinenissiessiiriiorviindideisri se 15 Wavelength Calibrations amp Dispersion Measurement
54. LastFrame on the Calibration Setup frame Initial S Range N A Syntax INSTMODE S1D Initial Buf b0 Dark and Flat are off Syntax LastFrmBuf 01112131415 Itime The amount of time the array is exposed between LastFrmSubDark off on readouts or the time interval for 1 Coadd The minimum LastFrmDivFlat off on value is determined by the readout rate Prompt Itime on the observing parameter s Obs MeanFrmBuf MeanFrmSubDark page MeanFrmDivFlat During a GO you have the option of Range 0 1 to 3600 0 seconds accumulating the data and displaying a mean frame at the Initial 1 end of each cycles These parameters allow you control over this option The MeanFrmBuf identifies the buffer in 8 16 94 Page 39 IRTF CSHELL User s Guide the VF program uses to display the mean frame If set MeanFrmSubDark and MeanFrmDivFlat will cause some processing of the mean frame by subtracting a dark and dividing by a flat frame The dark and flat frame are identified by the vf program as the data loaded into buffers 5 Dark and 6 Flat Note This option consumes much of the CPU s execution time and should only be used during GO with long integration times greater than 15 seconds Prompt Meanframe on the Calibration Setup frame Range N A Initial Buf N A Dark and Flat are off Syntax MeanFrmBuf 01112131415 MeanFrmSubDark off on MeanFrmDivFlat off on Object Name This information identifies the object you are obser
55. Local Globol Initial Syntax SAYScale Sets the range of the Y axis of a Spectra A graph when the autoscale option is fixed Y Scale Fixed on the main panel for SpectraA display 0 to 255 N A SAYScale min max Prompt Range Initial Syntax SaveSetup Saves some setup information to a file in the DoPath directory This file consisted of macor commands Prompt Range Initial Syntax Save Setup as a Marco File Frame Setup can be save using an legal filename N A SaveSetup filename SBDataYRange Sets the range of the Y axis of a Spectra B graph of the object and sky bin data Prompt Range Initial Syntax P 2432 to 2432 1 V SBDataYRange min max SBDiffYRange Sets the range of the Y axis of a Spectra B graph of the difference between the obj and sky bins Prompt Range Initial Syntax SBObjBin DiffYRange on the main panel for SpectraB display 2432 to 2432 1 V SBDiffYRange min max Sets the bin range of the object data for a Spectra B graph Prompt Range Initial Syntax ObjBin on the main panel for SpectraB display 0 to 255 N A SBObjBin min max SBShow Specifies the data to be ploted for a Spectra B graph Prompt Range InitialDOS Syntax SBSkyBin Show on the main panel for SpectraB display D Display a plot of the difference object sky bin O Display a plot of the Object bin S Display aplot of the Sky bin SBShow D101
56. Openlook User Interface If you have questions or comments concerning VF you may contact the author of the software via email at denault ifa hawaii edu or by calling the IRTF at 808 956 8101 Setting up your user account Since VF is an IRTF in house software application it is already installed on IRTF all workstations If you wish to have this application installed on your own workstation please see the IRTF computer staff for more information This section will cover the setup information needed on you user account to run this application To setup your account you will need to know where the application is stored on the hard disk Normally the IRTF will install it in usr local VF however you should check with the computing staff on this The directory usr local VF will be used as an example in this document 1 Setting the environment variable VFHOME Create a environment variable VFHOME to equal the name of the sub directory where the application is stored on your hard disk For example each user can place the following line in the login file to set VFHOME to usr local VF setenv VFHOME usr local VF 2 Startup configuration file vf init This step is optional but highly recommended When VF starts up it searches for the file vf init in your home directory If this file exist VF expects it to contain VF commands See VF Command Dictionary for the syntax Using an text editor you can place instructions in this file to co
57. S Note The letter DOS can be ORed inclusively Sets the bin range of the sky data for a spectra B graph Prompt Range Initial Syntax SkyBin on the main panel for SpectraB display 0 to 255 V SBSkyBin min max 8 16 94 Page 68 IRTF CSHELL User s Guide SBXRange Sets the range of the X axis of the Spectra B graph Prompt XRange on the main panel for the SpectraB display Range 0 to 255 Initial V Syntax SBXRange min max SBYAutoScale Sets the Y axis autoscale flag for the spectraB graph Prompt YAutoScale on the main panel for SpectraB display Range OFF Use DiffYRange and DataYRange to set scales ON Auto scale the graph using max and min of data Initial off Syntax SBYAutoScale off on SetBadMask Exams a frame and builds the bac pixel mask definition from it Good pixel are represented by O s the rest are bad pixels GetBadMask Index to Dframe 0 thur 4 All pixels are good GetBadMask num Prompt Range Initial Syntax SetPixel Changes the value of the pixel located at x y in the buffer on the active canvas Prompt N A Range N A Initial N A Syntax SetPixel x y value StatsCanvas Identifies the buffer used to in calculating the stats values by selecting the canvas holding the data Prompt N A Range Oto4 Initial 0 Syntax StatsCanvas AIBICIDIE StatsObjBox Set the size and position of the rectangle area which identifies the pixels call the ObjectBox
58. Sky OH Lines The following table list some night sky OH lines in the J H and K windows that might be useful for wavelength calibration or other checks Observed wavelengths are in vacuum bl denotes a blend and intensities are in units of photons st arcsec These data are taken from Ramsay Mountain and Geballe 1992 M N R A S 259 751 Also see this reference for more lines um 1 0063 1 0263 1 0824 1 1430 1 2092 1 2660 1 3072 1 4501 1 4582 1 4818 1 4873 1 5170 1 5235 1 5319 1 5403 1 5524 1 5578 1 5622 1 5814 1 5946 1 6018 1 6059 1 6108 1 6217 1 6330 1 6434 Transition tO tO tO tO tO R branch P 2 bl P 1 bl P 2 bl P A bl R 1 R 7 bl P 1 P 1 P 2 bl P 3 bl P A bl R 2 bl R 1 bl Q P 1 P 1 P 2 P 2 P 3 bl P A bl P 5 bl 9 5 4 1 5 2 6 3 7 4 8 5 8 5 2 0 2 0 2 0 3 1 4 2 4 2 4 2 4 2 4 2 4 2 Intensity 3399 6 2276 3 676 9 825 7 758 7 801 1 602 5 937 4 929 9 825 8 1123 3 1082 9 3884 0 3556 2 2572 8 2259 9 1708 6 2483 4 6715 0 1038 2 3749 9 1634 2 4375 7 2960 2 1678 8 1574 5 um 1 6489 1 6692 1 6891 1 6944 1 6992 1 7061 1 7101 1 7235 1 7367 1 7418 1 7639 1 9685 1 9756 1 9845 2 0270 2 0315 2 0400 2 0897 2 1110 2 1183 2 1250 2 1518 2 1792 2 1938 2 2108 2 2309 Transition R branch Q P 1 P 2 P 2 P 3 P 3 P 4 R bl P 5 R 2 R 1 bl Q R 1 bl R 0 R 0 P 1 P 2 P 2 P 5
59. Spect of Continuum Lamp 1 slit 1 2537 1300 with blockers in 1 6593 2709 2 1698 2906 3 5260 635 4 701 3807 8 16 94 Page 103 IRTF CSHELL User s Guide D Temperatures and Controllers The CSHELL dewar and optics are cooled by a liquid nitrogen bath which must be filled once per day usually at the start of each night A closed cycle cooler provides additional cooling for the arrays The arrays are maintained at their optimal operating temperatures by temperature controllers which apply small amounts of resistive heating to the devices It is the user s responsibility to keep an eye on the array cold box and grating temperatures The temperatures will drift if CSHELL runs out of liquid nitrogen if the controllers get reset or if the closed cycle cooler fails The cold box should be 72 5 2 K Temperatures any higher will cause focus and dispersion changes The grating is cooled by the same bath as the cold box so its temperature will usually follow the cold box Follow the troubleshooting procedures in Appendix B if the cold box temperature is out of its range The following procedures for resetting the temperature controllers should be performed by an IRTF operator or staff member only The detector array temperature controllers are located on the front side of Box 5 which is mounted on the telescope along with CSHELL The controllers usually have their set points reset to 0 K when powered off and their heaters are off when t
60. TCS Figure 18 The TCS Coordinates frame The following steps outline the procedures for offsetting the TCS 1 Enter the Angle and PlateScale information This information varies with the array and instrument used The following table contains the value for the IRTF Facility Instruments Please confirm these values with the Telescope operator during your run PlateScale CSHELL NSFCAM 0 3 0 15 or 0 06 User definable 2 Identify the From and To points in terms of their x y pixel location on the image This can be accomplisted by the following method a Manual type in the coordinated values b Drawing the XOR line on the image First place the cursor in the image at the From pixel location While pressing the SHIFT key press the middle mouse button and drag the cursor to the To location While you are dragging the mouse a line should be drawn between the two points The act of drawing this line updates the From and To coordinates values in the TCS Coordinates frame c Place the cursor in the image Click the left or SELECT mouse button to focus keyboard input into the canvas Now when you press the F to T key on the keyboard the coordinates of the cursor will be written to the From or To prompts in the TCS Coordinates frame 3 Press the Calculate Offset button Using the From To Angle and Plate Scale information the RA and DEC offsets are calculated The results as display in the Offset is ra dec prompt 4
61. VF Position Table 1 2 35um NBF Open AF4 BF 2 4 05um NBF Open AF4 BF2 3 He 1 083 Open AF2 BF4 4 HI 2 167 Open AF3 BF4 5 Blank AF5 BF5 6 Open AF4 BF4 7 CVF amp Blocker See CVF Position Table 8 2 35um NBF Blocker AF7 BF1 9 4 05um NBF Blocker AF6 BF2 10 2 5um Blocker AF7 BF4 11 4 lum Blocker AF6 BF4 When menu index 0 or 7 are select in order to use the CVFs the positions of the wheels are calculated from the following tables Search the table until you found the first row which include the wavelenght you are using The CVF Used column indicated which filter is used The step position are calculated from the coefficients found in the columns Motor Position Equations Terms For the other filter the Blocker or Open position is given by the Position of Other Wheel column Position of Other Wheel Motor Position Equations Terms From To CVF Used Blocker Open 1 100 1 570 ACVF1 BF6 BF4 10609 83 13495 61 0 1 570 2 449 BCVF1 AF7 AF4 1625 66 2838 23 1 48 2 460 4 100 BCVF2 AF6 AF4 2450 57225 1380 7596 0 4 100 4 350 BCVF2 AF4 AF4 Same as above 4 350 5 600 BCVF3 AF4 AF4 5354 37862 860 7481 0 8 16 94 Page 95 IRTF CSHELL User s Guide Figure 2 CSHELL Slit Wheel Inner numbers are degrees outer ones are motor step positions 54698 1181 a 51587 4925 8031 48487 sie T6 331 6 31 7 516 11142 45362 a 71 6 291 6 14254 ore 42254 271 6 251 6 16 J
62. ain panel An example of a canvas shown in figure 3 The information area shows some textual information about the data The left hand side shows the buffer the filename and the divisor variable For example B1 01jan0092 fts 6 means this canvas is displaying the data in Buffer B1 which contains the file 01jan0092 fts and that the data is represented at 1 6 of its true value On the right side additional information about the data or display is shown This information depends on the display type and is described in Table A The vertical and horizontal scrollbars allow you to scroll the display if the image is larger than the canvas Only the image and header display types can be scrolled All other display types are scaled to the size of the canvas The Canvas is used to show a representation of the data according to the display parameters In addition the canvas can capture mouse and keyboard events which can affect the display See Table A Description of Canvas Events for a description of the types of events for each display type Image Canvas event Action Cursor Movements Display the x y location and value fo the pixel in the information area The text is usually displayed in black However if the pixel is bad and the bad pixel mask is on the text is colored red Dragging the cursor and pressing the This causes the colormap to be stretched and shifted Vertical menu right mouse button movements affect the strech Horizontal mo
63. ameters mostly dealing with the array electronics Initial 0 Syntax PWINDOW 01112 Rotatelmage This option automaticly rotates the image clockwise 90 in the obsmode Stare and Nod Prompt None Enter command at command prompt Range Off No rotation performed On Rotates the image Initial On Syntax ROTATEIMAGE Off ON Samples This parameter identifies the number of samples or times the array is readout to obtain the image for 1 coadd Note that increased the number of samples will lower you noise but will also increase you minimum integration time This is a engineering or restricted command Prompt Samples on the Observing Parameter s Eng page Range 1 to 256 Initial 1 Syntax SAMPLES num SaveSetUp Ceates a macro file of some of the current parameter in the dofile directory This command is used only by the XUI program Prompt Save Parameters on the main menu access the Save Parameters as a Macro file Frame Syntax SaveSetUp filename SetMotorRdy This command sets the status for all the motorized items filter dit len pplate to the READY state This command is intended for engineering purposes only Since all item must in in a ready state before a GO is accepted this command clears any ERROR condition due to mechincal failures Do not attempt to move any motors which has been set ready using this command This is an engineering or restricted command Syntax SETMOTORDY Shutter Select
64. and does exactly what you want Commands to move the telescope TCS commands can also be included in CSHELLXUI Do Files See the IRTF document Computer to TCS ASCII Communications for a complete listing of TCS commands As an example the following macro will take an exposure offset the telescope 1 N expose again offset again expose again and then return to the original position tcs ABEAM tcs 1 0 0 0 0 1 C SCN echo Base Position go tcs 10 0 1 0 1 C SCN wait 2 echo Moved 1 arcsec N of Base go tcs 10 0 2 0 1 C SCN wait 2 echo Moved 2 arcsec N of Base go tcs 1 0 0 0 0 1 C SCN echo Done Returned to Base 8 16 94 Page 77 IRTF CSHELL User s Guide D Observing Spectral Lines 1 Popular Astronomical Line List The following table lists the vacuum rest wavelengths of some commonly observed near IR lines and band heads Material HI HI HI HI HI H2 Hel Transition Name 5 3 10 4 9 4 4 3 8 4 1 0 2P 2S 4S 3P 1 0 7 4 10 7 1 0 zi 2 0 1 0 10 5 7 6 1 0 8 5 1 0 0 0 5 4 5 4 7 5 0 0 PB Pa Bd S 2 S 1 By S 0 S 1 bh QG O 5 Pf Pfy O 7 S 13 PfB S 9 um 1 2822 1 7367 1 8179 1 8756 1 9451 2 0388 2 0587 2 1126 2 1218 2 1661 2 1891 2 2233 2 2477 2 2935 2 4237 3 0392 3 091 3 2349 3 2970 3 7406 3 8074 3 8462 4 0490 4 0522 4 6538 4 6946 8 16 94 Page 78 IRTF CSHELL User s Guide 2 Night
65. are The first step of the discharge lamp wavelength calibration process is selecting which calibration lamp lines to use Lines must be selected for calculation of the spectral zero point and dispersion at each observational wavelength grating position selected CSHELL s spectral range is only 1 400 of the central wavelength This narrow range dictates that the lines of the calibration lamps rarely fall on the arrays when the instrument is set up to observe lines of astronomical interest We can trick CSHELL into observing these calibration lines at the same grating position as used for astronomical lines however The procedure is to select the vacuum 8 16 94 Page 15 IRTF CSHELL User s Guide wavelength which you wish to fall near the center of the array for your astronomical observations and then select a different grating order so that the desired calibration lines are visible without moving the grating This is accomplished by moving the CVF filter to select different orders after the grating has already been positioned for the desired astronomical wavelength This technique is explained below An auxiliary program cal_lines is used to determine which calibration lamp lines are to be used at a given wavelength selected for observation This program is run from either a UNIX command line window on an IRTF workstation or else from the PC in the IRTF office at Hale Pohaku Instructions on using the program and a description of its ou
66. asic Acquires single images with just the basic options SIM Simulation mode Allows the software to be used with out the actual camera hardware Initial Basic Syntax CAMMODE basic sim ChgClkBias Changes the bias voltage to the clock bias DAC This is an engineering command Prompt ChgClkBias button on the Observing Parameter s Engineering page Range Board 1 to 4 DAC 1 to 16 Volts 10 to 10 Initial N A Syntax CHGCLKBIAS board dac volt CoAdd The number of intergrations summed together per beam or chop position in a GO Prompt Coadd on the observing parameter s Obs page Range 1 ti 32000 Initial 1 Syntax COADD num Color Indicate to the IC program whether the console supports color for text output The character attributes for color or monochrome are selected based on this parameter Prompt None Range OFF or ON Initial OFF Syntax COLOR off on Comment Specifies a string to be place in the fits header of the saved file as a comment Prompt Comment on the observing parameter s Obs page Range Any string up to 40 characters Initial Undefined Syntax COMMENT string Cycles Cycles is a repeat factor in a GO sequence under basic mode For the ObsMode Noiselmage Cycles indicates how many frames will be used to calculate the noise Prompt Cycles on the observering parameter s Obs page Range 1 to 1000 Initial 1 Syntax CYCLES num CVFwlen When a CVF filter is selected
67. ation from the file header Therefore it is best to have Autosave enabled before acquiring any data if you wish to save it The Object and Comment fields in the Observing parameters Frame are also written into the file header One must issue a Go command to take an exposure This is usually done by selecting Go Obs from the Go menu of the cshellxui Base Frame main window This is also the default for that menu so Go Obs can also be selected by clicking the left mouse button when the pointer is positioned over the Go menu The data goes into the chosen buffer default LastFrame buffer is b0 and is written to a disk file only if Autosave is enabled The data buffer can be displayed in a canvas of the vf window Canvas A displays buffer b0 by default The current image coordinate and data value of the image pixel beneath the mouse cursor is displayed at the top of the image The image can be zoomed rescaled or restretched in its vf display window canvas and it can also be redisplayed as a spectral cut histogram or file header in any vf canvas See the vf documentation in III A for details A Before Night Time Observing System Checkout The IRTF day crew checks the basic wavelength calibration sensitivity and overall functionality of CSHELL each time it is mounted on the telescope but you can also check these parameters when you do wavelength calibrations at the start of each night The presence of the calibration la
68. ats frame The stats command frame consists of an information area and a panel area The information area displays the sum mean and standard deviation of the data display in a canvas The mean variance and standard deviation for the entire frame is displayed on the top row Below this are 3 columns labeled Object Sky and Object Sky with statistical values for each column The object column displays the value on the object box The sky column displays statistics on the sky box If the object and sky box are of equal dimension the object sky column will display statistics on the pixel values obtained by subtracting the object box from the sky box The Stats frame s panel contains the following control items The Canvas button identifies the canvas The data display in this canvas is used to generate the statistical information Selecting the Set Sky button sets the location and size of the sky box to be equal to the object box Clicking on the Hide button will cause the frame to disappear On the bottom row are special button used with NSFCAM There button allow a user to set the size and position of the subarrays used in the various mode of NSFCAM The position and size of the ObjectBox is sent to NSFCAM s Guide array or SubArray 1 2 or 3 when you select the Guide Array1 Array2 or Array3 bottons 8 16 94 Page 58 IRTF CSHELL User s Guide The Edit and Execute Command Files frame VF provides a way of creating and executing D
69. ay as well as configure the telescope focus off axis guider and on axis TV camera focus and crosshair position for CSHELL Select the proper detector and perform the system signal and noise checks as well as the wavelength calibrations detailed in SILA if you have not already done so 8 16 94 Page 17 IRTF CSHELL User s Guide General Observing Procedures The general observing procedure is to image the field of your object after completing a telescope slew Next you must position the telescope so that your object is on the slit of the spectrometer and then switch to spectroscopic mode Note the position of your object on the CCD camera display and ask the operator to start auto guiding on it You may use an off axis guide star if your object is invisible on the CCD You will usually acquire spectral data in frame pairs with frames on and off of the object It is convenient to nod the telescope by about 15 along the slit between the on and off frames This allows the object to be observed in both frames of a pair if the object is not spatially extended Be sure to nod far enough away from the object so that pixels seeing the object in the on frame see nothing but blank sky in the off frame The telescope operator can enter the magnitude and direction of the nod for you and the cshellxui software will automatically nod the telescope between exposures if you observe in nodding mode Keep exposure times short initiall
70. ay Bias Voltages The IR detector bias must be programmed to match the observing application Using a single fixed bias as done with the old NICMOS array is inappropriate because of non linearities and icky pixel artifacts in the SBRC 256 x 256 InSb arrays Larger biases allow more electrons to be collected before saturation but they also cause increased numbers of high dark current pixels icky pixels and low level non linearities Fortunately the icky pixels mostly disappear when object and sky frames are subtracted Dark frames with exposure times equivalent to flat fields should be taken to subtract these pixels from your flats The SBRC InSb arrays are not particularly linear near the tops or the bottoms of their integrating wells see Appendix F but linearity problems can be avoided if you expose your flats so that they have similar data counts to your object frames You may coadd many flats to achieve high S N I recommend that you pick one of four following detector bias settings for you observations Observation Bias mV Well VDDUC VDET XUI Do File Most Spectroscopy 325 5000 3 7 3 375 small Bright Thermal Spectroscopy 500 8400 3 7 3 200 medium Bright or Thermal Imaging 800 15 500 3 7 2 900 large Thermal Imaging with very 1000 21 300 3 7 2 700 huge high backgrounds Notes Well The maximum number of ADU counts 1 ADU 11 0 electrons that can be collected while not departing more than 1 from the linearity relation of the m
71. bservations In practice this means that you should acquire several frames of the continuum lamp s spectrum at each wavelength and slit size employed in your astronomical observations Continuum lamp spectra exposure times of about 5 seconds result in about 2000 counts through a 1 slit You may take many flat frames 10 by typing the number of frames in the Cycles text field of the Observing Parameters Frame The first step in this process is resetting the grating order or CVF wavelengths of CSHELL from those used for calibration lines to those used for your astronomical observations All flat field and data frames should be taken without moving the grating or CVF between exposures All exposures include a dark current contribution from the detector arrays This current can be a significant fraction of the signal from astronomical objects since CSHELL operates at very high resolution Objects are normally observed in frame pairs on and off the source which are subtracted to remove this dark current contribution from the data We must observe separate dark frames to remove this component from the flat fields however This is done by turning off the calibration lamps and closing the shutter before acquiring frames of exposure time equal to the flat field frames Again many 5 10 dark frames should be acquired at a time in this manner Astronomical Observations You are ready to acquire astronomical data once you have completed your calibration lamp
72. change the Directory by editing this text panel item Filename The data will be written to this filename You may change the filename by editing this field Save Selecting this button commands VF to write the data to the file Hide Selecting this button will cause the command frame to disappear 8 16 94 Page 56 IRTF CSHELL User s Guide The Math Frame Selecting the Math button from the Main menu will cause the Math command frame to appear on the screen This command frame allows 3 types of operations 1 Arithmetic on the pixel values 2 Transferring data between buffers 3 Deleting data from a buffer and 4 Rotating an image Note that there are buttons labeled Math CopyBuf Clear and two icons while contain rotation directions These icon performs the operations Near these buttons are various panel items used to identify the buffer or other parameters for each operation CopyBuf lt bo to lt bo Clear lt bo PJ bo Hide Figure 15 TheMath frame For buffer Arithmetic form an expression by selecting a destination buffer operation and the operands The first operand is always a buffer index the second can be a buffer index or a constant Selecting constant from the menu allows you to enter a value for the second operand Two examples of math expressions are shown b2 b0 b1 will subtract buffer 1 from buffer 0 and store the results in buffer 2 b2 b2 100 will mul
73. d then FTP back to hubble ifa hawaii edu to get the files you want We plan to update the archive contents regularly and we welcome your submissions 8 16 94 Page 84 IRTF CSHELL User s Guide F CSHELL Data and its Reduction 1 CSHELL FITS File Header Example SIMPLE T DATA IS IN FITS FORMAT BITPIX 16 bits per pixel Two comp Integers NAXIS 2 NUMBER OF AXIS NAXIS1 256 PIXELS ON lst MOST VARYING AXIS NAXIS2 256 PIXELS ON 2nd MOST VARYING AXIS DATAMIN 82 MIN DATA VALUE IN FILE DATAMAX 2795 MAX DATA VALUE IN FILE DATAMEAN 12 MEAN DATA VALUE IN FILE ASEC_PIX 0 20 PLATE SCALE in arcseconds pixel DIVISOR 1 Normalization value ORIGIN Institute for Astronomy TELESCOP NASA IRTF INSTRUME CShell Spectrograph OBSERVER Your Name OBJECT HD129653 K 6 92 COMMENT Comment for fits frame IRAFNAME hd1290019 a BEAM A Object A or sky B IMAGETYP object Type of image TIME OBS 11 50 38 06 UT TIME OF ACQISTION hh mm ss ss DATE _OBS 07 05 94 UT DATE OF ACQUISITION dd mm yy ITIME 60 0000 INTEGRATION TIME IN SECONDS CO_ADDS 1 NUMBER OF INTEGRATIONS OBSMODE 1 obsmode is Nod AB CYCLES 1 Number of cycles INSTMODE 0 Instrument Mode is S GPOS 235523 Grating step position GANGLE 63 509 Grating Angle ORDER 26 User s Order GWLEN 2 17000 Grating s wavelength FILTER 0 Filter is CVF Wlen Open CVFWLEN 2
74. der an example of using these commands to determine which calibration lines to observe if one is using the UNIX window on the Sun XUI computer If we wish to observe HI Br y 2 16609 um wavelength we issue the command cal_lines 2 16609 lpr which prints the following cal_ lines table on the system printer Central Vacuum Wavelength 2 166090 microns 4616 613 cm 1 order 26 waveno line vac um obs um order CVF um col SBRC 256 Argon lines 6040 898 1 655383 2 164732 34 1 6564 56 6040 500 1 655492 2 164874 34 1 6564 63 7287 392 1 372233 2 163906 41 1 3736 15 7457 021 1 341018 2 166260 42 1 3409 133 7456 983 1 341025 2 166271 42 1 3409 134 Krypton lines 5321 816 1 879058 2 168144 30 1 8773 228 5321 150 1 879293 2 168415 30 1 8773 242 5502 887 1 817228 2 166695 31 1 8167 155 5502 884 1 817229 2 166696 31 1 8167 155 5856 639 1 707464 2 167166 33 1 7066 179 5856 272 1 707571 2 167302 33 1 7066 186 5856 275 1 707570 2 167300 33 1 7066 185 6032 254 1 657755 2 167833 34 1 6564 212 6393 989 1 563969 2 165496 36 1 5644 95 6573 027 1 521369 2 165025 37 1 5221 71 6929 652 1 443074 2 164611 39 1 4441 50 6929 652 1 443074 2 164611 39 1 4441 50 7276 638 1 374261 2 167104 41 1 3736 176 7276 638 1 374261 2 167104 41 1 3736 176 Xenon lines Very Faint 5321 059 1 879325 2 168452 30 1 8773 243 5856 272 1 707571 2 167302 33 1 7066 186 5856 275 1 707570 2 167300 33 1 7066 185 6039 008 1 655901 2 165409 34 1 6564 90 The first line of the o
75. ducing a frame called normflat 2 Object Data a form differences A1 B1 A2 B2 B1 A1 B2 A2 e g IRAF imarith b combine the differences for each beam to give an A image and a B image e g IRAF imcombine c divide each by the normalized flat field e g IRAF imarith d correct for badpixels with the mask e g use fix cl IRAF script e Examine the images for any additional bad pixels or other problems f You may save disk space by stripping out NICMOS image areas where there is no data e g use strip cl IRAF script 3 Do the same for the standard star data if any 4 Extract the Spectra The IRAF noao twodspec apextract package is well suited to this The three extraction steps can be done interactively at once with the APALL task dispaxis 1 a EDIT the aperture and width and any background regions subtract b TRACE the aperture defining its position as a function of position across the frame c EXTRACT the one D spectrum from the frame 5 Extract Calibration Spectra based on spectral lamp data Assuming n gt 1 images with n gt 2 lamp lines often in different orders a combine the images to be used e g IRAF imcombine or imcopy 8 16 94 Page 86 IRTF CSHELL User s Guide b extract a calibration spectrum for each beam A B such that the calibration data are extracted from the same part of the image as the object data Do this using APALL setting referen and profile to the object da
76. e Save j Hide Figure 10 Save Parameters Frame The panel items inside this frame are DoPath This text panel item identifies the sub directory used for accessing command or macro files You may change this directory by editing this panel item Filename The macro file is created using this filename You may change the filename by editing this field Save Selecting this button will execute the SaveSetUp command which crates a macro file using your current setup Hide Selecting this button will cause the frame to disappear from the computer screen 8 16 94 Page 33 IRTF CSHELL User s Guide The Edit and Execute Files frame XUI provides a way of creating and executing macro files A macro file is a text file containing commands There should be 1 command per line and the syntax for commands are defined in the CSHELL XUI Command Dictionary In the Options sub menu the choice Execute command files brings up a command frame to create or edit files and execute them vy Do Files DoPath fhorme wirth denault macro s ui DoFilemask Record On Update File List Load file Clear text Save as cshelltest Pwindow O LastSave j ITIME 1 000 cshelltest ae cshelltest T obsmode 0 demo WaveLen 1 39013 LastFrmBuf 0 Paparms Lamp Off p parms CCD Out setmotorrdy ele 7 setmotorrdy Se ace est kd Execute Cancel Figure 11 Do Files command
77. e IC executes on a 386PC computer located on the telescope platform and is responsible for the real time control of the instrument and its electronics The user s interface is provided by the program named cshellxui or commonly referred to as the XUI The XUI executes from a SUN workstation and provides a friendly interface to the camera These two programs communication over an ethernet network allowing you to control and view data produce by the instrument from any IRTF s SUN workstations Figure 1 illustrates this setup Telescope s ethernet network XUI amp VF Observer on workstation in observer s room IC Instrument Control execute on PC at telescope platform Figure 1 IC and XUI diagram CSHELL A word about initialization files and environment variables This section describes the initialization files for the IC and XUI program Normally you will not need to modify these files since default values are automatically setup for your account They are described here so that you may modify them as needed Or so you can check them if thing are not working An environment variable CSHELLXUI identifies the location of the XUI executable and associated information file For example if the cshellxui application is stored in usr local cshell XUI the following line in your cshre file would correctly setup this variable setenv CSHELLXUI usr local cshell XUI The IC XUI and VF all use a similar method to initialize parame
78. e also contains ark current and other detector artifacts These must be removed and therefore sky measurements are required However one loses about half of the total available observing time because of this Second any standard star measurement will cover only a few of the rows that the extended object covers Hence the quality of the results may depend more on the quality of the flat fields than anything else It may be advantageous to use the Moon as a flat field source if it is an appropriate standard and you might want to drift scan over it during exposures to smooth over any spatial features However keep in mind that the Moon has many solar absorption lines and it has albedo variations along the slit It is far from being a satisfactory flat field but it may be handy for spectral regions that are relatively free of solar lines if you can find a relatively uniformly illuminated patch of the Moon The moon should make a good telluric calibration source in the thermal IR gt 3 um It is possible to automatically move the telescope a specified amount between exposures in order to map extended objects For example you can move in a vector parallel to the slit and 1 slit width in size between each exposure This is done by writing CSHELLXUI macros Do Files that include TCS commands Consult your support scientist or T O for help with this 11 Command Files After taking data with the CSHELL you will find that many tasks are repetitive s
79. e quality of your data divide data by standard stars to remove telluric lines or rotate a spectrum 180 so that you can compare it to a frequency spectrum You can also combine the data of the A and B beams in a differenced spectrum with the Spectra A or Spectra B displays If your object is in both beams in a differenced spectral image you are nodding along the slit then define a box enclosing the A beam as the object and a box enclosing the B beam as the sky and select subtract sky to see a display of the summed data VF also can edit and execute command files This feature is convenient for performing frame arithmetic on and displaying data once they are loaded into buffers Several VF command files are provided for your use 8 16 94 Page 22 IRTF CSHELL User s Guide lll CSHELL Instrument Reference A CSHELLXUI and VF Software Description and Reference B Turning CSHELL On and Off C Observing Techniques D Observing Spectral Lines E IRTF Computer Services F CSHELL Data and its Reduction G Using the CSHELL CCD Guider Camera 8 16 94 Page 23 IRTF CSHELL User s Guide A CSHELLXUI and VF Software Description and Reference 8 16 94 Page 24 IRTF CSHELL User s Guide What is the IC and XUI The software for CSHELL consist of 2 applications the Instrument Control IC program and the X User s Interface XUI The Instrument Control is named cshellic or commonly referred to as the IC Th
80. eated by simply pressing the Go button in the cshellxui main menu you need not re load and re execute the file since the state of CSHELL has already been set by the command file It is most efficient to use command files for all of your observations but keep a close eye on the exposure time Autosave status and other instrument parameters it is quite easy to start an integration with the instrument in the wrong state For example you may wish to save images of the field but the image command files turns Autosave off Common VF Quick Look Techniques The data in any buffer can be examined using the VF program For example suppose a spectral frame is stored in buffer bO and canvas A of VF is set to display an image of the buffer bO data Canvas C can also be set to point to buffer bO and its display mode set to SpectraA or Spectra B in order to show a binned spectrum of the data over some range in coordinate values Draw a box on the image in canvas A and select the Obj Box and the X scale buttons in the canvas C panel to show the spectrum of the data in the canvas A box in a graph in canvas C These and other techniques are described in the VF documentation III A A hard copy of the image or the spectrum shown in the selected canvas can be obtained by selecting the print button at the bottom right of the VF window You may also perform frame arithmetic on and rotate images with VF For example you can co add images to evaluate th
81. ent appropriately hostname cshell hostname cshell manoa b Look for the following line Mount remote NFS directories using the following format mount remhost rem_dir_path_name local _dir_path_name mount wirth home wirth home wirth The mount command should be commented on the summit 8 16 94 Page 35 IRTF CSHELL User s Guide CSHELL XUI IC Command Reference Array Set the size and location of sub arrays to be readout for r the next GO These coordinate are relative to the physical device You data is normally viewed rotated 90 clockwise Prompt Array_icon on the Parameters screen OBS page Range x y wid hgt The x y location of the upper left corner and its width and hgt is specified Please note that these values must be multiples of 8 Initial Full size 0 0 256 256 Syntax ARRAY x y wid hgt AutoSavelC Determines whether the data is saved by the IC program Prompt Parameters window in the Setup page Range Off Data is not saved by the IC On The IC program on the PC saves the data Initial Off Syntax AutoSavelC off on AutoSaveXUI Determines whether the data is saved by the XUI program Prompt AutosaveXUI on the observing parameter s Obs page Range Off Data is not saved by the XUI On The XUI program on the SUN saves the data Initial Off Syntax AutoSaveXUI off on CamMode Specifies the clocking and readout modes in the GO sequence Prompt N A Range B
82. ep position GRATINGPOS 100000 to 400000 Syntax Range GratingRMove Moves the grating from its current position by a relative number of steps 2000 to 2000 GRATINGRMOVE steps Range Syntax GWLen Moves the grating to the indicated wavelenght First the optimum order is calculated The user s order is set to the optimum order Then the step position of the grating is determined from the inputted wavelenght and this order The grating is moved to this position Prompt See WaveLen command 8 16 94 Page 38 IRTF CSHELL User s Guide 1 0 to 6 0 GWLEN micons Range Syntax ICHostName The XUI program uses this hostname when initiating network communication to the IC program This command can only be executed from the XUI program Range Enter the hostname of the IC computer Initial cshell Syntax ICHOSTNAME name ICPath The path identifies the subdirectory the IC program uses when writing data files This command will create new subdirectories if path doesn t exist Supports the DATE and HOME macors Range Any legal unix subdirectory 80 chars max Initial HOME data DATE Syntax ICpath string ImageNumber An ID number used to create the filename See Filename for an example Prompt Next Image Number on the observing parameters Obs page Range 1 to 9999 Initial 1 Syntax IMAGENUMBER num InstMode Places the instrument in Spectrocopic or Direct Imaging mode by moving the Direct Imag
83. errrrsresssssseseeee 104 E Summary of Upgrade Changes for Previous CSHELL Users 105 E IR Array Linearity Dgtg 2 nn n at a o ave A mua E 107 8 16 94 Page 4 IRTF CSHELL User s Guide I Introduction This document is meant to be a reference to the CSHELL spectrometer for IRTF observers operators and staff Sections I and II of this document are also intended to serve as a guide to introduce new users to the instrument These first two sections prepare the user describe the instrument and cover the basics of system startup wavelength calibration and data acquisition Section III is a detailed reference to instrument operation observing techniques spectral line selection data archiving and data reduction The appendices in IV include data log sheets spectral line setup forms instrument hardware information a troubleshooting guide temperture controller setup instructions and a summary of changes implemented in the 1994 CSHELL Upgrade CSHELL users control the instrument through a Sun workstation computer using data acquisition and quick look reduction software under the Sun Open Windows graphical user interface GUI The Sun computer communicates via TCP IP over the observatory Ethernet network to an instrument control IC computer mounted on the telescope with CSHELL Normally the IC machine is always on and running the CSHELL software but the observer logs onto the Sun machine each night to
84. es mylib addlib additional libraries mylib fitslib fits libraries In each of these directories there is a makefile Use the make utility to compile these libraries Currently there are 3 different makefile depending on your OS makefile sun makefile lynx makefile linux If you are compiling these programs on a SUN there command would do the job cd mylib addlib make f makefile sun cd mylib fitslib make f makefile sun o dP dP 4 After the libraries are done You can compile the VF application Go to the VF directory and type make to compile the program Note You may need to modify the makefile to compile in your enviroment cd vf make 5 Edit the following startup files for each application vf init VF s startup file Please refer to the VF user manual for further details If you have question comments please contact me I would be happy to help you Tony Denault IRTF Programmer email denault galileo ifa hawaii edu Telephone 808 956 8101 Mail Institute for Astronomy 2680 Woodlawn Drive Honolulu HI 96822 8 16 94 Page 63 IRTF CSHELL User s Guide VF Command Reference Active Sets the active canvas Prompt None Buttons on the base window allows you to change the active canvas Range A B C D or E Initial A Syntax ACTIVE id BadMask Enables disables the Bad Pixel Mask BadMask OFF or ON OFF BadMask OFF ON Prompt Range Initial Syntax Comme
85. es each frame separately with a a or b name extension to indicate beam polarity A single cycle in nodding mode acquires one frame in position A and another frame in position B Multiples of two cycles cause data to be acquired in the ABBA position sequence The nod direction and magnitude are set to your request by the telescope operator Newly acquired data goes into one of several buffers and may also be automatically saved The LastFrame buffer in the Observing Parameters Frame indicates which buffer new data will go into Buffer b0 is the default new data buffer and the vf quick look program displays this buffer by default in its Canvas A This is the standard configuration for data to be displayed in the top left canvas of the vf quick look program A MeanFrame buffer can be selected so that a VF window shows the mean of a sequence of cycles e g mean A B in Nod mode or mean A frame in Stare mode Autosave must be enabled for data to be automatically written with the concatenated filename and number shown on the bottom line of the Observing Parameters Frame Autosave is enabled by checking its box this ensures that the data files will be saved onto the Sun XUI computer s disk in FITS disk format The data in a buffer can also be saved by the vf quick look program The Save Data option of the vf File menu will save a selected buffer as a FITS data file but will omit the instrument and telescope inform
86. et x 0 Yo Zoom on O bjBox 1 ShowScale Off On Print Image Figure 4 The Main Panel The panel items display in figure 5 will never change These are described below a cle Cmd ColorMap gray cm ejo Inverse ColorMap Display Image Buffer bo Figure 5 Active Canvas Buttons The selected button identifies the active canvas The remaining panel items reflect the set up of the active canvas Changing the values of any of the panel items only affects the active panel items Command Line This text panel item allows you to type commands to vf The vf commands are listed in the VF Command Dictionary Colormap This list item allows you to select one of the may predefined colormap defintions Inverse ColorMap This button inverse the current colormap Display This pop up menu item selects the display type for the active canvas The display types are Image SpectrA SpectraB Header HistoGram Linecut and XLinecut Buffer Each canvas will display the data from this buffer You can view the data in a different buffer by changing this panel item However the rest of the panel may change depending on the Display parameter For each display type a different set of parameters is displayed These panel items reflect the parameters of the current active canvas and display type A description of the panel items for each display type is given below with an illustration of its panel The Image Display option
87. frame The following panel items will help you read edit and save the contents of macro file DoPath This text panel identifies the sub directory where your macro files are stored DoFileMask The file mask is a regular expression used with the path to determine the names of the files displayed in the file list Selecting Update File List will re initialize the list Load File Selecting this reads the file selected in the file list and places the text in the edit window Clear text Clear the edit windows buffer Save as Selecting this button writes the current text in the edit window into the filename shown in the text panel item Record This check box panel item controls the recording function When the box is checked any commands executed by XUI will also be written to the edit window This allows you to write macro files using the mouse and panels items The file list is identical to the one in the Execute Command Files frame The sub directory and file mask is specified by the DoPath and DoFileMask variable which are shown in the Execute frame To execute a command file select the file in the list then click on the Execute button XUI will read the file and execute each line The commands and its error message Error None when successfully executed will be written to the Feedback panel on the Application s base frame so you can see what s happening If you wish to abort a macro file in progress click on the Cancel button
88. he controllers are initially powered on The arrays will cool to 20 K and will not be operational if the set points are not set and if the heaters are not turned on The day crew properly sets the array temperatures and powers on the heaters when they mount CSHELL on the telescope but you must set up the controllers if you have powered down Box 5 due to approaching lightning or as part of a troubleshooting procedure The following procedure illustrates how to read the array temperatures set the set points and turn on the heaters Controller A controls the SBRC InSb array temperature 30 0 K set point and Controller B controls the TEK CCD array temperature 175 K set point The controllers may be set up either via their front panel controls Procedure A or else via software Procedure B Procedure A Front Panel Configuration Read Array Temperature on controller front panel LCD display T1 probe Press ENTER button until set point field is selected S xxx x on display Press ENTER to change the set point temperature Press SCROLL to change current digit press ENTER to accept and move to next digit Press RETURN to enter the displayed temperature as the set point Press RETURN to activate the heater The green HEATER LED should light Procedure B Software Control Alternatively you can read and set the array temperatures via the cshellxui software eRead the array temperatures and set points in the cshellxui main window eChange the set po
89. he path identifies the subdirectory where you will ni read and wirte data files a A P t Path d subwind Syntax LineCutyyyxy romp ath on pene su win ow Range Any legal unix subdirectory Initial data Math Performs simple artimetric on the images a a i Prompt Math button on the Math subwindow yn ua eine Range N A eer ME Print This command produces a postscript file of the Initial N A we graph or image in a canvas window and sent this file to the Syntax Math B B 4 1 1 1 B 1 num 8 16 94 Page 66 IRTF CSHELL User s Guide printer specified by the printer variable This postscript file is named lastprint Prompt Each printable graph has a Print button on the main panel Range AtoE Initial N A Syntax Print AIBICIDIE Printer Identifies the printer used by the print command Prompt Printer on the setup subwindow Range Enter the name of a postscript printer on the network N A Printer name Initial Syntax PrinterType For hardcopy of image this command specifies either a color or black amp white postscript output Prompt Printer Type on the setup subwindow Range 0 B amp W Postscript printer 1 Color Postscript printer Initial O Syntax PRINTERTYPE 011 Quit Exits the vf program Prompt Quit on the main menu Range N A Initial N A Syntax Quit Read Read a fits file from the current path into the buffer Prompt The Load Fits button on the Read Data
90. he slit is rotated enter the angle as defined in this convention in the TCS Coordinates frame of VF This will allow you to easily position any object in the imaging field onto the slit by pushing the mouse buttons see II B and II A for details Please consult with your Support Scientist or Telescope Operator if you need to rotate the instrument 8 16 94 Page 74 IRTF CSHELL User s Guide 9 Integrations and Nodding Prior to integrating check the XUI path for the proper data location and change all of the appropriate parameters in the Setup Parameters window frame These items need be checked only once each time the cshellxui software is started up Next check and change if necessary the following parameters Integration time eCoadds Cycles Observing Mode eLastFrame Buffer eMeanFrame Buffer eAutoSave EXAMPLE Take the case of Integration time Coadds Cycles Observing mode eLastFrame Buffer MeanFrame Buffer Seconds per exposure Number of exposures per beam Number of iterations of the selected observing mode Stare or Nod Buffer into which the last exposure is stored Buffer into which the average of the cycles are stored Check to have data stored into XUIpath directory 2 0 1 4 Nod b0 bl This will generate 2 0 sec exposures one exposure per beam and 4 AB pairs for a total of 8 separately stored exposures in ABBAABBA sequence The last exposure is in buffer b0 and the ru
91. here Note only one person at a time can start the IC program Please check with the Telescope Operator or Instrument Tech before staring up the IC program The procedures for starting the IC program are as follows 1 Log in on the IC computer host name is cshell as the user cshellic a Find the keyboard amp screen for the cshell IC computer Login as the user cshellic There is no password for this account login cshellic After hitting return it takes about 90 seconds for the software to startup and display the status screen See Figure 2 for an example of the IC s status screen Once this screen is display and all mechanisms show READY you may go ahead and start the XUI If any of the status show an ERROR state you should try to reinitialize the item using the init command i e FilterInit GOInit GratingInit etc If this fails ask assistance from the T O or support scientist to trouble shoot this failure CSHELL Instrument Control 2 0 Ape 27 19943 Time 14 09 22 Acg OK CycLeft 0 Filter 0k Grating OK Shutter 0K DIMirror OK VCCD OK Lamp Ok SocketIO OK Itime 1 000 GPos 200000 SetPt Heat 28 0073 10 Samples 1 EncoderPos 200000 Templ 26 00 Coadd 1 Gilen 1 39013 Temp2 51 00 GAngle 61 89 SetPteHeat 4 00 0 00 ObMode Stare Ay Order 40 Tempi 55 00 Cycles 1 Opt Odr 28 Temp2 62 00 InstHode 0 5 gt Slit 5 Blank Shutter 0 Close gt YCCD tOut DTime 2 00 CVFWlen 1 40000 LampMirror Q tOut Tbl_usec 0 Filter 5 Blan
92. i Observing Parameters Window icons representing the elements in the instruments optical path Icons representing elements exposed to light are colored yellow ones not in the light path are gray and the filter wheel is colored blue when the CVF has been manually changed to select a grating order different from the one of the entered wavelength One must select the proper states of each mechanism by selecting from each icon s menu with the mouse right button for menu Typical mouse menu operations with the icons are turning the calibration lamps on and off moving the lamp mirror in and out of the beam selecting the desired filter choosing a slit size switching between imaging and spectroscopic modes open and closing the shutter and switching between the detector arrays It is best to evaluate and change the states of the icons from right to left order as displayed in the window Different observing modes are selected by changing the configurations of CSHELL s mechanisms Open the shutter if you wish the detector array to be exposed to incident light but close it if you wish to acquire dark images The direct Imaging Mirror must be moved into the light path if one wants an image of the focal plane and it must be out of the light path if one wishes to acquire a spectrum Spectra are usually taken through a 30 long slit of selected width the slit width determines flux and resolution and images can be taken of a large field 30 x 30 through the o
93. id well range VDET amp VDDUC are detector biases Volts that can be typed into the SETUP Parameters frame of the CSHELL XUI Application XUI Do File is the name of a command file that can be executed from the Options menu of the CSHELL XUI application These files automatically set the indicated bias levels The bias voltages must also be set execute DO File or push button in Setup Parameters Window when the software is started You must also use blockers if you ovbserve with the 1 10 1 57 um CVF see 9 this section 2 Check For Read Noise Limit and Saturation The minimum background limited data value of each array is equal to the square of its read noise in electrons divided by the number of electrons per ADU This value is approximately 100 for the SBRC InSb array in CSHELL as listed in I Table 3 Try to keep your data numbers above these values to avoid being limited by array read noise The SBRC InSb array saturates at a level that is a function of detector bias as listed in the above table Try to keep raw data values below the listed 1 linearity departure levels It is good practice to check unsubtracted exposures for saturation This may occur in frames with low mean counts if there is a bright OH line or thermal telluric line that is not seen in the A B images 8 16 94 Page 72 IRTF CSHELL User s Guide NOTE When using the Direct Imaging Mode you may find a black spot in the center of a bright star This is a
94. in panel for SpectraA display Range 25 to 25 pixel units Initial O Syntax SaShift num SASkyBin Sets the range of rows to be used as the sky bin in the Spectra A graph Prompt SkyBin on main panel for SpectraA display Range O to 255 Initial 0 Syntax SASkyBin min max SAStats Indicated whether to show the graph or a table of statistical information for each line 8 16 94 Page 67 IRTF CSHELL User s Guide Prompt Stats on the main panel for SpectraA display OFF Displays the graph ON Display the table OFF SAStats off on Range Initial Syntax SASubtractSky This flag indicates whether to subtract the mean sky values from each object bin in the SpetraA graph SASubtractSky on the main panel for SpectraA display Range Off or ON Initial ON Syntax SASubtractSky off on Prompt SAXScale Sets the range of the X axis of a Spectra A graph Prompt XScale on the main panel for SpectraA display Range 0 to 255 Initial V Syntax SAXScale min max SAYAutoscale Select which option is used for determining the maximum and minimum values of the Y scale Prompt YAutoScale on the main panel for SpectraA display Fixed Used the asYScale values Local Each spectra graph used its own maximum and minimum value to set the y scale Range Globol A maximum and minimum value from all the spectra lines is found and is used for the Y ax s Globol SAYAutoscale Fixed
95. ine Note that the summing of columns in the ObjBin and SkyBin occurs before the subtraction Shift Enter a positive shift to the right or negative shift to the left number to shift the x axis in the graph Stats When the stats flag is on the graph is replaced by a table This table displays for each bin the row making up the bin the number of data point in the bin the mean value of those points the standard deviation of the point and the ratio of the mean and standard deviation YAutoScale Y Autoscale whichcan be fixed local or globol indicates how the scale for the Y axis of the graph is determined Y Scale Fixed This is the range of the Y axis when YAutoScale is fixed X Scale These values control the minimum and maximum values of the X Axis Print SpectraA Graph Select this button to prints the Spectra A graph The SpectraB Graph is produced by binning two rows of pixels One bin is the Object and the other is the Sky The mean value for each column can be displayed The Object graph is the mean column value of the object bin The Difference graph is the mean column value of the object bin minus the sky bin The SpectraB panel consists of the following items Display Spectra B Buffer bl Set ObjBin 59 to 33 Diff Range 100 to 500 Set SkyBin 100 to 149 DataYRange to 500 Show Diff Obj Sky Set XScale 9 to 255 YAutoScale Off On Print Spectra Graph Figure 8 The
96. information is kept in the directory pub IRTF CSHELL This directory contains instrument documentation including this manual data reduction information and some IRAF scripts and bad pixel masks that are useful in reducing CSHELL data The current directory contents are kept in the README txt file Currently the CSHELL directory contains two directories one for documentation and one for IRAF data reduction aids The Docs directory contains the files starting ps I and II of this CSHELL User s Manual swref ps Z CSHELLXUI and VF documentation II A of this manual data txt Text of Data Reduction Guide in III F 2 of this manual line_form ps CSHELL Line Set Up Form from Appendix A of this manual logsheet ps CSHELL Logsheet from Appendix A of this manual manual_v2 ps Z This entire CSHELL User s Manual manual_v2 word Z CSHELL User s Manual in MS Word format Macintosh 5 1 Here is how to access the information in IRTF On line First log on to IRTF On line by typing the following commands on your Internet host ftp irtf ifa hawaii edu orftp 128 171 79 135 use anonymous when prompted for Name and use your email address as a password Now switch to the CSHELL directory cd pub IRTF CSHELL List the files in the directory ls Retrieve the README txt file which describes the CSHELL archive contents get README txt End your session quit You may read the README txt file on your local machine to see what is in the archive an
97. ing mirror out or in Prompt Instrument Mode menu is accessed by clicking on the Grating or DiMirror icon on Parameter s Observing page Range S Spectroscopic Optical path is through grating Syntax ITIME sec Lamp Turn off on the calbration lamps This command automaticly move the lamp mirror out when the lamps are turned off and in when the lamps are on Cal_Lamp icon on the Parameter window s Observing page Prompt Range off AR Argon Lamp KR Krypton Lamp XE Xenon Lamp Cont Continuum Lamp Blank LAMP off AR I KR XE Cont Initial Syntax Lamplnit The command to initialize the lamp and lamp mirror by turning the lamp off and moving the mirror out of position Syntax LAMPINIT LampMirror More a mirror so the calibration lamp are out or in the optical light path Range Out lamps are out of optical path In lamp are in optical path Syntax LAMPMIRROR outl in LastFrmBuf LastFrmSubDark LastFrmDivFlat These are switches used by the XUI program to process each frame of data during a GO operation LastFrmBuf identifies the buffer in the VF program which will display the data When set LastFrmSubDark and LastFrmDivFlat will cause some processing of the data frame by subtracting a dark and dividing by a flat The dark and flat frames are identified by the VF program as the data loaded into buffer 5 Dark and 6 Flat D Direct Imaging Blocks the grating Prompt
98. ing the TO to View or automatically guide with the CSHELL CCD The observer should repeat this step whenever a new object is acquired The observer will not be notified of CCD hardware timeouts or be annoyed by guider frame beeps when the Guider XUI is not running This is a good thing 3 The TO should use the IRTF guide program to autoguide with CSHELL The rotation angle for the CSHELL CCD guider should now be approximately within 3 degrees the same as the CSHELL IR slit rotation angle entered into the VF TCS Coordinates Window by the observer This angle is the position angle on the sky of the top of the CSHELL slit as seen in VF 4 If the gic software has a hard failure e g unrecoverable socket errors then the TO should shut down the gic software type die and a lt CR gt in the gic window and restart the gic If errors recur then shut down the gic exit from cass pc login to cass pc as oroot and then reboot casspc with the reboot a command Wait a minute or so and then login to casspc as guider and restart gic The guider software commands follow 8 16 94 Page 88 IRTF CSHELL User s Guide GIC GUIDER XUI Command Reference do_stats Sets the calculation of stats on the DSP Syntax stats Off On do_array Sets the array type Syntax array 64 512 do_scale Sets the type of scaling on the DSP Syntax scale None Fixed Auto Slice do_autodata Sets the transfer of 32 bit data from
99. ints by typing the tempcmd A 300 or tempemd B 1750 commands on the cshellxui command line for the IR array and CCD respectively See III A for details eTurn the heaters on or off by typing the tempcmd A X or tempcmd B X see p 98 command on the cshellxui command line Heater status in the cshellxui window will display ERROR if the heater is off or the heater voltage if it is on See II A 8 16 94 Page 104 IRTF CSHELL User s Guide E Summary of Upgrade Changes for Previous CSHELL Users CSHELL Upgrade User Documentation Addendum I New InSb Array CSHELL now has a single IR detector array a 256 x 256 pixel Hughes SBRC InSb device It performs at least as well as the old NICMOS 3 array in nearly all respects while it also has increased spectral response better quantum efficiency and reduced artifacts less residual image and no corner glow The new array results in the following performance parameters 1 5 6 um response 16 5 total spectroscopic throughput 2 2 um 700 km s spectral range per exposure when grating at blaze angle 0 20 arcsec pixel and 2 7 km s pixel R N lt 33 e Idark 0 5 e ADU The new array also requires some operational changes Foremost the detector bias must be programmed to match the observing application Using a single fixed bias as done with the NICMOS array is inappropriate because of non linearities and icky pixel artifacts in the SBRC 256 x
100. its design is such that its optical axis has been translated by 0 56 cm from that of the incoming beam This produces a 1 12 cm displacement of the incoming and outgoing beams The dispersed light is directed to flat number 3 The distance between the secondary and primary mirrors of the collimator is 12 6 cm which is enough for installation of a direct imaging mirror shown in Figure 2 When inserted into the beam this mirror sends the beam back to the collimator forming an image of the focal plane at the IR array The telescope focal plane can thus be viewed directly in the IR and the slit positioned before a spectrum is taken It is also be possible to record an image of the field if desired There is little room for placement of an IR array at the image of the spectrum so we allow the dispersed light to expand to a spherical relay mirror via flat number 4 The relay mirror forms the final image of the spectrum on the IR array A pupil image is located about 3 cm in front of the IR array where there is a stop and pupil mask to reject stray light The closed cycle cooler allows continuous operation for three weeks or longer on the telescope We are using a CTI Cryogenics Model 350 CP closed cycle cooler that provides acooling capacity of 20 watts at 77K and 2 watts at 13K A vibration damping mount was developed to reduce compressor induced microphonics CSHELL now uses a single Hughes SBRC 256 x 256 InSb pixel IR array to acquire all infrared
101. iversity of Hawaii The IRTF has made available to the community various manuals forms programs etc via this FTP site This has come to be know as IRFT Online A copy the this manual and the source code to VF is available from IRTF online To access IRTF Online 1 Perform an anonymous FTP to irtf ifa hawaii edu 2 cd to pub IRTF 3 Download and review the README txt file This contains a brief description of all files in IRTF Online In the directory pub IRTF VF are the files related to the VF application Here is the README txt file from this directory Hello this readme file contains note for those IRTF online users who are interested in VF VF is a simple FITS viewer it was developed by the NASA Infrared Telescope Facility for use with their data acquistion systems We are making the binaries and source code available on IRTF online IRTF online is an anonymous ftp site Irtf online is located on irtf ifa hawaii 128 171 79 135 The pub IRTF VF in this directory are 8 16 94 Page 61 IRTF CSHELL User s Guide REAME txt This file vf source tar Z The source code necessary to compile vf vfi doc tar Z The user guide to vf in MS Word MAC and a Postscript format Notes on VF s Docmentations The file vf doc tar Z contains a copy of VF User s Guide in MS Word for the MAC and postscript format 1 ftp the vf doc tar Z to your home directory 2 uncompress and un tar this file ie uncompress vf source ta
102. k gt Lamp iOFF gt ISPLdTbl 1 AutoSavell OFF Filename data ImageNumber 001 AutoSavexUT OFF IfPath home wirth denaultdata 28apr I Figure 2 IC program Sample Screen Starting the XUI Once the IC program is running and all status is READY you may start the XUI program The XUI program is an X windows applications Here are the steps to start the cshellxui 1 Login on the IRTF s sun workstation and start Openwindows Your support scientist should have given you instruction on obtaining an account To start Openwindows type openwin at the UNIX prompt openwin 8 16 94 Page 26 IRTF CSHELL User s Guide 2 From OpenWindows bring up the workspace menu by clicking the right mouse button on the workspace area Under CSHELL select the Cshell XUI item oH Workspace Programs P Cshell XUI 3 Utilities WF Properties Cshell XUI ENG Exit Login to Cshell IC computer Figure 3 Starting the XUI from the Workspace Menu For those of you who were told to start up the engineering version select the menu item CShell XUI ENG from the menu Figure 3 If all goes well the following window should appear on your screen CSHELL X User s Interface v2 0 Apr 27 1994 Parameters T Gor Options Stop Quit Status Motors Tempe lt About avelen 2 0 no error Command wavelen 2 0 no error Figure 4 XUI program Sample Screen 3
103. lained in detailed here but it is suggested you check them out 8 16 94 Page 29 IRTF CSHELL User s Guide The Parameter s frame The Parameters frame allows you to view and edit the most common CSHELL parameters These parameter are separated into 3 groups Observing Setup and Engineering The first set of blue buttons on the Parameter s frame allows you to switch between these groups You may view edit each set of parameter by selecting the proper group Each time you select a group the Parameter s frame appearance will change to display the appropriate parameters The Observing Parameters When you select the Observing button on the Parameter s frame it will display the most common parameters used while observing Figure 6 is an illustration of the frame for Observing FS parameters Observing Setup Engineering Int time sec 1 000 Wavelen 1 39013 um 7193 55 cm i Coadds 01 Cycles 01 CVF WLen 1 40000 Obs Mode Stare A G ng 83 LastFrame Buffer bo _ Dark MeanFrame Buffer N A _ Dark Object Name of object Comment Comment for fits frame XUIPath scri data cshell Filename data Next Image Number 0001 AutoSaveXUl _ On Figure 7 Observing Parameter Frame The row of icons in the middle of the window represent mechanical components in the optical path From left to right each icon represents a component which can alter redirect block the light as it enters the CSHELL
104. ld using this directory Prompt Path on the Execute Command File Frame Range Any legal unix subdirectory Initial N A Syntax DoPath string FileMask Set the filemask variable for the File Read subwindow Prompt Filemask Range Any string fts FileMask string Initial Syntax HeaderCol For the Active Canvas it sets the starting column of the fits header to be displayed Prompt none Range 0to50 Initial 0 Syntax HeaderCol num HeaderRow For the Active Canvas it sets the first lint of the fits header to be displayed Prompt none Range Oto 50 Initial O Syntax HeaderRow num HistArea Sets the range of pixels to be included in the histogram Prompt HistArea on main panel Range All All the pixels in the frame are used Box The pixels include in the ObjBox are used Initial All Syntax HistArea All Box HistBin For the Active Canvas it sets the number of bins for a hisogram display Histbin Range 1to100 Initial 20 Syntax Prompt HistBin num ImageOffset For the Active Canvas it determines which pixel is displayed the the upper left corner for a image display 0 0 identifies the first pixel of the fits data Offset X and Y Also these values can be controlled a canvas s scrollbar Prompt Range 0 to size of axis in the fits frame Initial 0 0 Syntax ImageOffset offx offy ImageRange For the Active Canvas it sets the minimum and maximum values for the colormap
105. le Voltage button on the Setup page The user s must set these voltages manually before take data with the SBRC array 8 16 94 Page 31 IRTF CSHELL User s Guide The Engineering Parameters When you select the Engineering button on the Parameter s frame the engineering parameter are displayed These are parameters which should not be changed by casual observer The Instrument Technician or support scientist can change them after inputting the password You can view these parameters at anytime but they can only be changed after the password has been entered Figure 8 is an illustration of a sample frame vy Parameters Observing Setup Engineering epassword Engineering is Restricted DSP Reset Msec 1000 Sample Mode Single Double DoFastMode off on Slow Cnt 1 Samples 1 SubArray 0 64 256 128 TempRecord otf on ChgclkBias Board Figure 9 Engineering Parameters Frame For a detailed explanation of the options for each panel item see the CSHELL Command Dictionary 8 16 94 Page 32 IRTF CSHELL User s Guide The Save Parameters as a Macro File frame Selecting the Save Parameter menu item from the Parameters sub menu causes the Save Parameters as a Macro File command frame to appear Through this frame you can create a macro file of the current setting of the following parameters gy Save Parameters as a Macro File DoPath f home wirth denault macro ud Filename LastSav
106. lecting Update File List will re initialize the list Load File Selecting this reads the file selected in the filelist and places the text in the edit window Clear text Clear the edit windows buffer Save as Selecting this button writes the current text in the edit window into the filename shown in the text panel item Record This check box panel item controls the recording function When the box is checked any commands executed by VF will also be written to the edit window This allows you to create macro files using the mouse and panels items To execute a macro file select the file in the list then click on the Execute button VF will read the file and execute each line The commands and its error message Error None when successfully executed will be written to the Feedback area located on the bottom of this frame If you wish to abort a macro file in progress click on the Cancel button 8 16 94 Page 59 IRTF CSHELL User s Guide The TCS Coordinates The TCS Coordinates frame allow you to calculate the relative offsets in RA and DEC between 2 pixel in an image This offset can be transmitted to the Telescope Control Sytem thus providing a convient way to position objects on the array To bring the frame up select the TCS Coordinate menu item from mainmenu s Options button TCS Coordinate Angle 279 PlateScale 0 28 From x y 12 34 To xy 50 125 Calculate Offset Offset is ra dec 2548 10 64 Offset
107. ly near column 100 Move the telescope to the object you wish to acquire Move the slit to the open position Take an image of the field and note the position of your object on the array x y coordinates Use the Options menu of the VF program and select TCS Use this window to compute the telescope offsets you need to center the object on the slit the center of the slit will be near row 100 Note the position of the object in the CCD camera field when it is centered in the slit You may mark this position on the TV monitor Remember to insert the CCD filter VCCD icon in CSHELLXUI if the CCD bleeds due to excessive object brightness 8 Slit Rotation The slit is normally positioned in the East West direction The primary reason for this is that tracking errors will not usually lead to a loss of signal To obtain any other rotation angle the entire instrument must be rotated using the IRTF instrument rotator This requires manually rotating the instrument a procedure taking at least 15 minutes and not something to do often The default East West slit position causes North to be located to the left and East down in the VF image display on the Sun workstation The top of the slit as seen in VF is then rotated 270 East of North and this angle is the default value in the VF TCS Coordinates frame The slit location in the VF coordinate system is drawn on the bottom of the CSHELL cryostat for easy reference while rotating the instrument Once t
108. m lt lt 4 um or else observing the dome target with the dome lights on We do not yet have much experience in acquiring good flats at gt 3 um wavelengths 4 Focus And Collimation The collimation settings should be the same as that used for NSFCAM Check with the T O to make sure that this is the case The focus should be checked on a 7 9th magnitude star which the T O can find in the on line SAO catalog Use the Direct Imaging Mode slit in the open position and a few seconds of exposure time using several coadds of shorter integrations if necessary to integrate over seeing At the beginning of the night the focus is usually about 270 with the chipped secondary 2 10 with the milled secondary and it systematically drops as the temperature drops to about 2 30 1 85 with milled secondary by the end of the night The stellar image is typically less than arcsec full width half maximum less than 5 pixels FWHM 5 Tweaking the CVF for a Flatter Flat Whenever a new wavelength is entered the grating and CVF are moved The CVF suffers from internal reflections which cause an interference pattern in all spectra The amplitude of this pattern varies from about 10 20 peak to peak and it is quite sensitive to small changes in CVF position If this fringing is particularly bad in your object or flat field data you can try to minimize it by moving the CVF wheel no more than 40 steps total in small increments 5 or
109. manifestation of gross saturation and the numbers in the black area are meaningless 3 Flat fielding Flat fielding is accomplished by taking spectra of a continuum source usually a light bulb that illuminates an integrating sphere the same one that is used for the calibration lamps One typically should obtain flats at the beginning of the night whenever standards are measured and at the end of the night Flat fields should be taken for each observed wavelength observed The grating and the CVF should not be moved between observing objects and flats in order to minimize wavelength shifts and ripples in spectra caused by interference in the CVFs For most work obtaining about 10 flats at an exposure of 1000 counts should suffice They have similar data counts to your object frames if you are very concerned about linearity For work requiring S N 100 one should strive to get 25 30 flats at a time Flats must be acquired with the same detector bias setting as your object data We usually use the continuum lamp to generate flat fields at wavelengths lt 2 5 um The lamp does not produce many photons in the 3 5 um range due to opaque glass but it usable Its glass bulb is warm enough to provide an abundance of photons in the gt 4 um region You may also wish to try taking flats at gt 4 by using the thermal emission of the dome or mirror covers You can try either taking long exposures of the continuum lamp or mirror covers for 3 u
110. med Herschel so 4 mm tapes must be written on the summit Herschel s UNIX device name for the 4 mm tape drive without compression is dev rstO or dev nrstO Tar writes data into 20 block records by default The following examples show how to archive your data onto either drive Sometimes we store data in other directories besides scr1 cshell data illustrated below if your data is in a different directory you must substitute its name in the following commands ARCHIVING I NIGHT S DATA Commands cd scri1 cshell data ls tar cvf dev rst0 directory 8 16 94 Page 82 IRTF CSHELL User s Guide These commands will switch to the CSHELL data directory list the nights there and copy your night s data onto the tar tape You must substitute your night s data directory name for directory in the above tar command You should see the name of this directory when you execute the above Is command These directory names are usually of the form ddmon e g 30aug ARCHIVING SEVERAL NIGHTS DATA Commands cd scrl1 cshell data ls tar cvf dev rst0 datel date2 PRINTING A TAPE S TABLE OF CONTENTS Commands tar tvf dev rst0 or tar tvf dev rst0 lpr The first command will list the names of the files of a tape archive to the Sun computer screen The second command will print the names of the files on the system laser printer The second command may take 10 20 minutes to execute without any confirmation until the pages are p
111. mp lines at the proper locations and intensities as well as the proper appearance of the flat field and dark frames are adequate assurances of the proper functioning of the instrument The IRTF day crew and support staff have priority in using CSHELL between 9 00 am and 3 15 pm while observers have usage priority at other times Before the first night s observing starting after 3 15 pm we recommend that the signal and dark frame noise checks and the wavelength calibrations be performed either at HP or at the telescope This will provide you with hands on experience with using the instrument before taking astronomical data and allow you to spot any problems early on 8 16 94 Page 14 IRTF CSHELL User s Guide Call the IRTF summit before starting any work with the instrument from Hale Pohaku the day crew or other staff may be using it First start up the cshellic cshellxui and vf software see III A B or get assistance from the IRTF staff Once the cshellxui software is up you should check the main window s status panel for proper instrument operation Remember to type xuihostname wien in the command line of the cshellxui window if observing from the IRTF workstation wien at Hale Pohaku All of the status items should be OK or READY green The IR array temperature should be 30 0 0 2 K The CCD array temperature should be 190 20 K The coldbox temperature should be 72 5 2 K There should not be any warning message
112. nfigure when it starts up VF For example the file may contain the following instruction to setup the directory paths and printer name Path S HOME protodat FileMask img DoPath S HOME macro v DoFilemask IRTF CSHELL User s Guide printer irlabpr Starting VF The VF program is a Xwindows application You should be running an X server on your console Openwindows is the default X server for sun workstations There are two methods to start VF 1 Starting VF using the workspace menu The workspace menu has been configured to include a selection to start up an instance of the VF program Press the menu or right mouse button on the workspace to bring up the workspace menu Then click on Cshell with the menu button to display its submenu Select VF with the select left button to begin execution of the VF program 2 To start VF from a xterm or shelltool window type vf in the window unix vf amp At this point the base window of the application should appear on your screen Sometimes the following message may appear in your console window Run VF without Sockets y or n lt CR If you are running VF with the instrumentaion software you must run VF with sockets Otherwise you may run VF without sockets When VF starts it tries to establish a socket to allow data and commands to be sent to it from the instrumentation program This message can appear because 1 VF is already running on the machine 2 The ope
113. ngth Remember to change the CVF wavelength to the correct value see Cal_lines Table in III D before observing each calibration line The spectral zero point and dispersion at the 2 16609 um wavelength may be calculated by performing a linear fit to the apparent line wavelengths obs column 3 of Cal_lines Table in III D and the array columns in which they appear at the row of interest It is best to repeat this procedure for each wavelength you plan to observe but it is possible to only observe single lines at each wavelength for spectral zero point information and compute the dispersion from the Bry dispersion using the above formulae Be sure to record the grating angle for each line which can be read from the cshellxui program s main window This angle is also in the FITS file headers see III F Repeat this calibration procedure each night of your run B Observing at the Telescope Once you arrive at the telescope you may want to enter the coordinates of your target objects and standard stars into the user star catalog of the IRTF DAS This will save you from doing so later while you are observing Your telescope operator or support scientist can help you type in the coordinates The Telescope Operator will fill CSHELL with liquid nitrogen and bring up the CSHELL software each night for you Be sure to ask the telescope operator to rotate CSHELL to your desired slit angle default is East West with North to the left on the VF displ
114. nning average of the AB pairs will appear in buffer b1 For each AB pair the telescope nods from position A to position B on the sky The amount the telescope nods is set by the Telescope Operator so inform him about how far you wish to nod in arcsec Motion E W or N S or both directions is possible for the nod We recommend that you nod point sources along the slit with a throw of about 15 in order to acquire object data in both the A and B frame positions You must select the CVF Blocker Option and also use the shutter wheel blocker SPF when observing with the 1 1 1 57 um CVF This CVF transmits gt 2 5 um radiation causing significantly increased background in your data if not blocked as prescribed The blockers impart about a 10 reduction in flux over the 1 1 1 6 um region NOTE Every exposure is stored onto the disk if the Autosave is enabled The exposures are automatically named by the filename and the image number For example if the filename is set to data and the image number is 0010 then the above example produces 8 files named data0010 a data0011 b data0012 a data0017 b The extensions a and b refer to the A and B beams 8 16 94 Page 75 IRTF CSHELL User s Guide 10 Observing Extended Objects When observing extended objects there will be additional concerns First if the object fills the slit the object must be moved off the slit for observations of the sky Note that the sky exposur
115. ntations Get one 4mm or 8 mm tape for each night of your run Read I and II of this manual Daytime at Hale Pohaku or the Summit Obtain an IRTF guest observer account log into IRTF workstation as guests Select Calibration Lamp lines with cal_lines Start the CSHELL Software and Check the System Status Set Programmable Voltages Setup Parameters Frame Take Signal and Noise Test Data Take Calibration Line Data for all Grating Settings that night At The Summit Request CSHELL Rotation Focus Guider and Crosshair Configurations Enter Personal and Instrument Setup Information into CSHELLXUI and VF Software Select bias macro and Set Programmable Voltages Setup Parameters Frame Select First Wavelength Image Sky or Ar lamp through Slit and Record its Column Position Direct Imaging Mode Take Flat Field and Dark Frames Spectroscopic Mode Slew to Object Image Object Move Slit to Open and Select Direct Imaging Mode Choose Nod Vector for Imaging Take Image Frame Pair of Object Move to Slit using VF TCS Coordinates Window Take Object Spectra Insert Slit and Select Spectroscopic Mode Locate Object along Slit and Choose Nod Vector Guide with CCD Camera Take First Spectrum short exposure and Evaluate Signal Take More Spectra longer exposures Slew to Standard Image Standard Move Slit to Open and Select Direct Imaging Mode Choose Nod Vector for Imaging Take Image Frame Pair of Object Move to Slit using VF TCS Coo
116. nts Events Display Modes BadMask ON BadMaskOFF Tracking cursor in Estimate bad pixel Display actual pixel image window values alues Display textinred Display text in black Estimate bad pixel values Display Actual pixel alues ark Bad pixles with x Estimate bad pixel se actual values values SpectraA SpectraB Histogram Line Cut Estimate bad pixel values Boxzoom Set the Image Zoom on the active canvas so that the object box fills as much as the canvas as possible Prompt Zoom on ObjBox on main panel Range N A Initial N A Syntax BOXZOOM Buffer Changes the data buffer associated with the active canvas Prompt Buffer on the main panel b0 to b7 Canvas A displays Dframe 0 Canvas B displays Dframe 1 ect Buffer B Range Initial Syntax Clear A command to set a data buffer to empty Prompt Clear button on Math frame Range bO to b7 Initial Undefined Syntax CLEAR B cminverst Inverse the current colormap definitions Inverse Colormap prompt on base window CMINVERSE Prompt Syntax ColorMap Reads in a colormap definition from a file Prompt Colormap on the main panel Standard colormap files are a cm COLORMAP filename Range Initial Syntax CopyBuf A command to copy data from one buffer to another Prompt Copy button on Math sub window BO to B7 Undefine COPYBUF B to B Range Initial Syntax DarkFlat A command to compute dest
117. o files A Do or macro file is a text file containing commands There should be 1 command per line and the syntax for commands are defined inthe VF Command Dictionary In the Options submenu the choices Execute Do files brings up a window to allow you to create edit and execute Do files This frame contains a text edit window a feedback window and a group of panel items at Do Files DoPath f home wirth denault macro vf DoFilemask Record _ On Update File List Load file Clear text Saveas demo Read jup_obj BO all zn Heed jup_0b B1 demo Read jup_sky B1 flat math b b b1 3 math b bo 1 noise Path fhomefwi rthydenault data protocam reduce Read uranus fts B1 TImageRange 15000 reduce Active B Image oom 4 ImageRange 35000 55000 Active C bisplayType 56 Buffer BO SBShow DOS SBv utoScale On Active D Buffer BO Execute Cancel Buffer Bi DisplayType G uffer BO no error uffer B1 no error isplayType G no error mageRange 28000 47000 no error ose COMMAND FILE at D no error Figure 17 The DO Files frame The following panel items will help you read edit and save the contents of DO file DoPath This text panel identifies the subdirectory where your macro files are stored DoFileMask The filemask is a regular expression used with the path to determine the names of the files displayed in the filelist Se
118. od observing mode after each object sky pair the difference frame is sent to the VF program If the Dark or Flat is checked a dark frame is subtracted from the data and it is divided by a flat frame The MeanFrame is also contain similar panels If you do a GO with cycles greater than 1 you can calculate the mean of all the frames sent to VF If a MeanBuffer is specified each time data is placed into Lastframe buffer the mean of all the frame in the current cycle is calculated an placed into this buffer The Dark and Flat specifies the processing done when calculating the mean frame In VF there are two special buffers a dark buffer and a flat buffer You must load data into these buffers if you specify the Dark or Flat options The Set Up Parameters When you select the Setup button on the Parameter s frame it will display parameter not normally used while observing but which should be reviewed during setup Figure 7 is an illustration of the frame for Setup vy Parameters Observing Setup Engineering Set Programmable Voltages VDDUC 3 500 VDET 2 900 Observer Your Name ICHostname noelani IcPath fhome wirth denault data 29apr AutosavelC _ On BeamSwitch DTime 2 00 Figure 8 Calibration Set Up Frame The items are usually self explanatory For a detailed explanation of each options refer to the CSHELL Command Dictionary Special Notes Always select the Set Programmab
119. or ERROR modes instead Most mechanisms may be initialized by commands typed in from the cshellic or cshellxui machine keyboards see II A for details For example if the Slit process shows an ERROR or INIT condition that never clears in the cshellxui status window at startup then you can attempt to clear the condition by issuing the S itInit command Sometimes such initialization commands must be repeated several times to clear an ERROR or INIT state These initialization commands may also be executed if a mechanism generates an ERROR or continuous INIT state during normal operation INIT states sometimes take 2 or 3 minutes to clear to READY wait some time before attempting to re initialize the mechanism If a more serious errors occurs such as the filter or slit wheels not moving to the correct locations the shut down and restart CSHELL as directed in III B If this clears your errors then CSHELL is safe to operate If it does not clear your errors then you can force CSHELL to ignore the problem by issuing a setmotorrdy command see I A CSHELL will be OK to use if you do not need to move the offending mechanism The nature of a failure should be reported investigated and documented Filter and Slit Wheels Positions of filter wheels and the grating can be examined from the cshellxui Motors frame of the program s main window pane Motors can be commanded to go to specific step positions see commands in II A It is useful to try to mo
120. pen slit position or else through a narrower slit Filters must be selected for the desired wavelengths and the grating is automatically positioned at the correct angle when wavelengths are entered into the cshellxui software Calibration lamps must be turned on and the lamp mirror moved in to take wavelength calibration e g Argon or Krypton lamp or flat field continuum lamp frames All lamps should be off and the mirror moved out when acquiring astronomical data The calibration lamps and mirror are usually used just when taking spectral calibration data and the lamp mirror is moved in and out by repeatedly selecting the lamp that is on The filter wheels are usually set to the CVF Open gt 1 57 um or CVF Blocker lt 1 57 um position unless one is observing lines for which we have discrete filters installed Be sure to enter your name institution etc in the Setup Parameters Frame Window each time you restart the cshellxui software The vacuum wavelength or wave number to be observed is entered into the Observing Parameters Frame Parameters such as integration time the number of coadds per frame and the number of frames or Cycles to be acquired are also entered into this window s text fields 8 16 94 Page 13 IRTF CSHELL User s Guide Data can be acquired in either stare mode single frame a appended to the filename or else in nodding mode The nodding mode moves the telescope between frames and stor
121. r Z tar xvf vf source tar 3 A vf doc directory will be created with the following files vf rtf Rich Text Format copy of the User s Guide vf ps A postscript version of the User s Guide Notes on VF s Source Code The file vf source tar Z contains the sources to the View Fits VF program I have made the source code available to those who are interested in porting or running VF at their home institution And for those who are curious to seeing how the software is written VF wase developed on a SPARC station running Openwindows They are compiled using sun s acc compiler and XVIEW It was not intended to be very portable but if your workstation has an ANSI compiler and the XVIEW libraries you should be able to compile these programs These instruction assume you have some knowledge in developing programming in an unix enviroment If not you will probably need assistance from a programmer type To install and compile the source 1 ftp the vf source tar Z to your home directory 2 uncompress and un tar this file ie uncompress vf source tar Z tar xvf vf source tar The following files directories should be created in you home directory vf init startup file for VF mylib This directory contains the source to libraries needed to compile the IC XUI and Vf vf This directory contains the source the VF 8 16 94 Page 62 IRTF CSHELL User s Guide 3 Make the libraries There are 2 set of librari
122. rating system has not cleared the socket a previous version was using If you just exit the program it will take the operating system a few minutes to destroy the socket During this period you cannot establish another VF socket Just wait 30 seconds and try again And maybe again 8 16 94 Page 45 IRTF CSHELL User s Guide The Base Frame When VF starts a window called the base frame appears on your screen Figure is an illustration of the base frame The base window consist of the Main Menu 4 Viewing Canvases the Main Panel and a Feedback Panel J IRTF View Fits ver Apr 15 1334 File T Math Options Quit j 8 47 33 i I 42250 47000 ColorMap acm Inverse ColorMap Display histoGram Buffer b1 97 11 of the data is graphed Range 28000 to 47000 0 00 is less than low range Number of bins 1 100 50 2 9 is greater than high range Area All Box Print Histogram Image Range 26000 47000 ne error Figure 1 The Base Frame The Main Menu The main menu and its submenu selections are shown below with a summary their purposes File Math Options T Quit Read Data Stats Frame Save Data Save Seta Execute De Files TCS Coordinates Set Up Figure 2 Main Menu 8 16 94 Page 46 IRTF CSHELL User s Guide Description of Menus Here is a description of the menuing hierarchy File Brings up the file menu Read Data Bring
123. rdinates Window Take Standard Spectra Darks and Flats Insert Slit and Select Spectroscopic Mode Locate Standard along Slit and Choose Nod Vector Take Spectrum Close Shutter Take Dark Frames Open Shutter Select Continuum Lamp and Mirror Take Flat Field Frames Repeat Flat Object and Standard Observations at other Wavelengths Until Done Take any missing Calibration Flat Field or Dark Frame Data Blank CSHELL Filter and Slit from cshellxui Quit CSHELLXUI VF and Guider Software logout from Sun Archive Data 4 mm tape drive at summit 8 mm tape drive at Hale Pohaku 8 16 94 Page 19 IRTF CSHELL User s Guide Flat Field and Dark Frames Uniform celestial illumination does not exactly illuminate the detector arrays uniformly due to imperfections in the telescope and instrument optics Each detector pixel also responds to illumination differently causing further departures from a uniform system response However dividing astronomical data by a flat field made by exposing CSHELL to a uniform illumination source should correct for these response abnormalities as long as the system responds to light linearly The continuum lamp is a good source of spatially and spectrally uniform illumination and CSHELL behaves linearly as long as each pixel has about the same number of counts in both object and flat filed data Therefore we can take flat field frames by observing the continuum lamp with the same instrument state used for astronomical o
124. rinted and the tape is rewound be patient SEVERAL ARCHIVES ON 1 TAPE You may append data onto a pre existing data tape but this creates a new archive at the end of the existing one rather than appending the old one This makes the tapes more confusing to write and read and we do not recommend using his technique unless you must It is most convenient to use the drive without rewinding it use the dev nrstO0 device name if you go this route Sequentially enter any of the above commands once for each archive using dev nrst0 instead of dev rstO Rewind the tape manually when you are done mt f dev nrst0 rewind READING YOUR DATA TAPES You can usually read your data onto your home UNIX computer with the command tar xvf dev rstx where dev rstx is the device name of your 8 mm tape drive 8 16 94 Page 83 IRTF CSHELL User s Guide 3 Anonymous FTP and WWW Site Information The IRTF maintains an anonymous FTP site called IRTF On line providing remote access to documentation and data reduction aids for IRTF observers This site is on the machine irtf ifa hawaii edu 128 171 79 135 and the information on it is accessible through the FTP File Transfer Protocol service of the Internet If you have access to a machine on the Internet then you may retrieve copies of this information This archive is also reachable through the IRTF World Wide Web WWW home page http irtfweb ifa hawaii edu Check it out All CSHELL
125. s a shutter wheel position Prompt Shutter Range Open Close 2 5SPF Initial Close Syntax SHUTTER Close Open 2 5SPF ShutterInit This command initializes the shutter wheel by searching for it limit switch then moving the shutter to the closed position Prompt None Enter command at command prompt Syntax Shutterlnit ShutterPos Allows you to move the shutter to an absolute step position Prompt None Enter command at command prompt Range 0 to 4999 Syntax ShutterPos step Slit Select and moves to a slit wheel position Prompt Slit Range 0 5 1 0 1 5 2 0 4 0 Blank Open J H K L L M Initial Blank Syntax Slit 0 5 1 1 0 I 1 5 2 0 4 0 I Blank Open J IHIKILIL IM Slitlnit Initializes the slit wheel by moving it into the limit and then setting it to BLANK Prompt None Enter command at command prompt Syntax SlitInit SlitPos Move the slit wheel to a step position Prompt None Enter command at command prompt Range 0 to 64000 Syntax SlitPos step SlowCnt When DoFastMode is OFF the SlowCnt variable specifies the numbers of NOP s or delays in the DSP clocking algorithm This effectively slows down the clocking pattern which lowers the readout rate and read noise This is an engineering or restricted command Prompt SlowCnt on the Observing Parameter s Eng page Range 1 to 100 8 16 94 Page 41 IRTF CSHELL User s Guide Initial 1 Syntax SLOWCNT num Stop During
126. s has of the following item 8 16 94 Page 49 IRTF CSHELL User s Guide El uranuz Pai 12 111 63600 ja Display Image Buffer bo Scale Fixed Auto Range 100 to 256 zoom x1 x2 x4 xa PP Offset X 0 Yo Zoom on ObjBox ShowScale Off On Print Image Figure 6 The Image display amp panel items Image Scale The scale options are fixed or auto When auto is selected the Image Range is automatically adjusted to the minimum and maximum values of the data displayed in the canvas This adjustment occurs whenever the data in the buffer changes For fixed scale the program will never change the Image Range Image Zoom The zoom sets the zoom factor for the display Select x1 x2 x4 or x8 to set the zoom to 1 1 1 2 1 4 or 1 8 data pixels per screen pixels Zoom on box This button sets the zoom and adjust the scroolbars of the canvas so that the Object Box is centered in the canvas and all the pixels within the Object Box is display at the highest zoom level ShowScale Determines if an arcsecond scale is displayed along with the image Note that the necessay information is also needed in the fits header or else the scale cannot be displayed Image Range The color to the pixels are found by mapping the colormap to the minimum and maximum values of the Image Range ImageOffset X amp Y Indicates which pixel is display on the upper left corner of the canvas Print Image Select
127. s in the cshellxui feedback window The IR array bias voltages must also be set select Set Programmable Voltages button in Setup Parameters Window whenever the software is started Signal and Noise Checks Check the array noise performance by taking a 2 0 second dark shutter closed exposure Check the array noise by selecting the stats item in the vf Options menu Refer to Table 4 to see the means and standard deviations you should getting in a sub region box of a given size The array has adequate dark and noise performance if your numbers are consistent with the table values and you can now evaluate its response to signals Take a 2 second spectroscopic exposure of the 2 19085 um Krypton line through the 1 slit and check if your peak signal values are consistent with those in Table 4 The Krypton line should be in column 128 5 Table 4 Signal amp Noise Check Dark Frame Kr Line Frame Int time sec 2 0 2 0 Slit Blank Le Mean ADUs 0 0 10 50 x 50 pixel box Std Dev ADUs 3 5 50 x 50 pixel box Peak Signal ADUs 1200 Wavelength Calibrations amp Dispersion Measurement You must take wavelength calibration data each night by either observing rare gas discharge lamps or else by using telluric emission or absorption lines in your data itself CSHELL uses vacuum wavelengths and vacuum wave numbers only Be sure to correct rest wavelengths for any velocity shifts in your objects before entering them into the CSHELL softw
128. s up the Read Data File dialog box Save Data Brings up the Save Data File dialog box Save Setup Brings up the Save Setup dialog box Math Brings up the Math command window Options Brings up the Options menu Stats Frame Brings up the Stats window Execute Do Files Brings up thewindow to edit and execute DO files TCS Coordinates Brings up the dialog box to send offset commands to the TCS Set Up Brings up the Setup window Quit The Color Map Canvas shows the current color map in use Four Canvases Located on the base frame are 4 Canvases with horizontal and vertical scrollbars They are used to display the data stored in VF s data buffers The Main Panel The main panel is used for control or changing the various display options The Feedback Panel Selecting buttons or changing values of the various menu or panel item usually generates a command to VF to manipulate the data or change the display These commands and the error message from vf are displayed in the Feedback Panel In this way you can see the commands and responses generated by your actions 8 16 94 Page 47 IRTF CSHELL User s Guide The Canvas The canvases are used to display the data There are 5 canvases identified by the letters A B C D and E Canvases A to D are 256 by 256 pixels in size and are located on the base frame Canvas E is located in a command frame window which can be re sized To bring up Canvas E select its panel button on the m
129. t field and the left mouse button can be double or triple clicked rapidly to select either a portion or all of the text in that field Text can also be selected by positioning the pointer clicking the left button and dragging the pointer over the desired text Selected text is highlighted and will be replaced by whatever new text is typed on the Sun keyboard All text changes and commands must be followed by carriage returns to make them effective This is a very important and often overlooked item The two columns of keys at the left edge of the sun keyboard can also be used to manipulate windows that the mouse pointer is on top of Most of these are toggles so pressing the Front key will alternately place the window under the pointer either in front of or behind all other displayed windows See III A of this manual for further details on the CSHELL software 8 16 94 Page 5 IRTF CSHELL User s Guide A Preparations Before Coming to the IRTF a Read this manual I and ID b Contact your support scientist if you have any questions c Retrieve and read the cshellxui CSHELL user interface and vf quick look data reduction software guides if you are not a computer WIMP Windows Icons and Mouse Person If possible get the vf quick look data reduction program installed at your home institution and practice using it Instructions on how to obtain these user guides and programs electronically is given in M E Alterna
130. ta image and do not edit or trace the aperture We now have I dimensional spectra 6 Wavelength Scale Data using noao onedspec IRAF tasks a for each line in calibration spectra convert the line wavelength to the equivalent wavelength in that order done incal_lines program b use IDENTIFY to fit a wavelength scale to the spectrum c use REFSPEC to assign that wavelength scale to object spectrum careful to apply the A calibration to the A spectrum etc d use DISPCOR to produce a dispersion correct spectrum for each beam 7 Reduce the standard star data in the same way 8 Divide each object spectrum beam by the appropriate standard star beam 9 Combine All Spectra Since the A B beams will have in general different wavelength scales use the function COMBINE noao onedspec IRAF task which will resample the spectra and average them This is the final spectrum 10 Plot the final spectrum using SPLOT noao onedspec IRAF task which can compute equivalent widths display wavelenght and intensity units etc Extended Emission If your object is extended along the length of your slit then the standard point source spectral extraction technique outlined above will probably not work optimally First perform the frame arithmetic outlined in steps 1 3 above Divide the object and standard star data by the normalized flat Telluric correction you may divide the flat fielded object data by a flat fielded standard star frame
131. tatus there is a list of the various components of CSHELL which can take some time to change moving the filter from point A to point B or should be monitored like the amount of time left in an integration Each item may show 3 possible states OK This item is ready to receive commands BUSY 99 This item is currently in motion or in use A new command concerning this item cannot be issued until it has completed its current motion 8 16 94 Page 28 IRTF CSHELL User s Guide ERROR A malfunction has occurred either in software or hardware The software task should be initialized after inspecting the hardware related to that item For example a filter command will be accepted only when the filter status is OK After the command is accepted its status will change to BUSY While the filter is moving no new filter commands will be accepted and the percentage complete is updated to provide visual feedback When the filter has reached its new position the status will return to OK The SETUP shows some important setup parameters In the example the CSHELL is currently using the SBRC array TEMPERATURE displays the current temperature readings from the sensors There are 4 sensors and their values are shown in Kelvin Under the Status Canvas there are 4 buttons labeled Status Motors TempCntl About Selecting the different buttons will allow you to view the different status screen available There different format are not exp
132. ters when starting up Each program look for a special text file and execute the commands stored in that file These file are plain text file which contain one command per line You may modify them using your favorite UNIX editor The available commands set are documented in the Command Dictionary for each application IC XUI and VF This IC program uses cshellic init from in your current working directory The XUI program uses cshellxui init from your home directory i e cshellxui init The VF program uses vf init from your home directory i e vf init Starting the Software This section outlines the procedures for starting up the software Note that there are two version of the software 8 16 94 Page 25 IRTF CSHELL User s Guide 1 Observers version This version is the last version of the software which has been tested in an actual observing night at the telescope 2 Engineering version This version is under development or testing This version may contain new features but has not been fully tested yet You should use the observers version unless you were specifically told by your support scientist to use the Engineering version of the software The following sections describe how to start up both the observer and the engineering version Starting the IC Normally the Instrument Technician will start the IC program for you However in case of computer crashes or other problems the procedure is explained
133. the DSP Syntax autodata Off On do_cammode specify clocking and readout program Syntax cammode singleshot simulation do_coaddQ Set number of coadds on DSP Syntax coadd n do_color determine what character attributes the kbio process uses to update the parms window on stdout syntax color no yes do_cycles Set the number of image cycles on the DSP Syntax cycles n do_die quits the program Syntax die do_go Performs a GO starts integration sequence syntax go do_goinit send a init message to the GO task GO can be initialized at anytime syntax GOInit do_goreset send a RESET message to the GO task syntax GoReset do_itime Set integration time in seconds Syntax itime seconds do_zoom Sets the display window zoom factor Syntax Zoom mag o_window Sets the size and location of the stats display window Only this part of the array will be scaled and displayed Syntax Window xoffset xsize yoffset ysize do_range Sets the range for fixed scaling Syntax range min max ddo_senddata8 Asks guider to send 8 bit data Writes data to file guider img Syntax Senddata8 do_sendinfo Send status information Just a dummy since info is always sent Syntax Sendinfo do_register Set up the array control signals Syntax register Oxnn do_sync Synchronizes the DSP and TEK DEV Syntax sync do_slice Sets the LSB for slice
134. this button to get a hardcopy from the laser printer The SpectraA Graph is produced by grouping columns of pixels and producing a set of points where each point is the mean value of a row These points are graphed as a line The SpectrA panel consist of the following items Display Spectra Buffer bo Set ObjBin 50 50 tog3 _ Stats Off Set SkyBin 50 100 to 145 vautoScale T Global RowPerBin 10 Y Scale Fixed to 50 Shift 0 Set XScale to 255 Subtract Sky lt Off Print Spectra Graph Figure 7 The SpectraA display amp panel items SetObjBin Pressing SELECT on this button will cause the beginining and ending rows of the Object Box to be entered into the ObjBin parameters To the right of this button are text panel items which allow manual entry The number in parentheses equal to the number of rows in the ObjBin SetSkyBin Pressing SELECT on this button will cause the begining and ending rows of the Object Box to be entered into the SkyBin parameters To the right of this button are text panel input prompts which displays these values The number in parentheses equal to the number of row in the SkyBin RowPerBin This number represent the number of rows to bin together Each bin is used to create 1 line in the graph 8 16 94 Page 50 IRTF CSHELL User s Guide Subtract Sky When the subtract sky option is on each spectra line graph is the result of the object lines minus the sky l
135. ti RER R 82 1 IRTF Mauna Kea Computer Facilities a 82 2 Archiving Your Datas senenn nae e A sasata upaya 82 3 Anonymous FTP and WWW Site Information 84 F CSHELL Data and its Reduction aa asassssssssssssssssssssssssssssssse 85 1 CSHELL FITS File Header Example a sssssss ss 85 2 Data Reduction Guide with IRAF Examples 86 G Using the CSHELL CCD Guider Camera a aaarssssssssssssssa 88 GIC GUIDER XUI Command Reference 89 IV Appendices ncia esa esae ba stentade us uqu usis asas aysana sq aqasha EER E Saag 90 A Observing Log Sheet and Line Settup Form rrasrssssssssasssss 90 B CSHELL Hardware Referenc e a rioris spoenen eieiei iaai 93 CUTroublesho60n_ a uqa sassaqaassspayatiapyhayashaps E E RTE tea sss a es 101 Filt tand Slit Wheels inatasan u Aa A she oupgnetadeaeecscaaa ds 101 CSHELL Grating EquatI0BS u asyay anr iais 103 Verifying CSHELL Throughput ss esesessesseerrrersrrererrrrrrrerrerrerrrrerrene 103 D Temperatures and ControllefS u asss ressasiar eni i a s 104 Procedure A Front Panel Configuration rrasrsssssasssss 104 Procedure B Software Control ssssssssssesssssssserrrrrreeeerr
136. ting from the new array Most importantly you must select the CVF Blocker Option and also use the shutter wheel blocker SPF when observing with the 1 1 1 57 um CVF This CVF transmits gt 2 5 um radiation causing significantly increased background in your data if not blocked as prescribed The blockers impart about a 10 reduction in flux over the 1 1 1 6 um region Now exposures can be as short as 076 s or even less The bias voltages must also be set DO File or push button in Setup Parameters Window when the software is started 8 16 94 Page 105 IRTF CSHELL User s Guide II New Tek 512 x 512 Acquisition amp Guide CCD The old surveillance CCD has been replaced with a scientific grade Tektronix 512 x 512 pixel CCD The CCD is operated via IC and XUI programs like other IRTF instruments It can be operated in a continuous mode for acquisition a single exposure mode or an auto guide mode Use of the guider software is described in II G of this manual The CCD is clocked at a rate of 333 000 pixels sec so it takes just under 1 second to read a frame this limits the minimum exposure time also A 1000x attenuation filter can be switched in front of the CCD for observing bright objects Pixels can be binned 1x1 2x2 4x4 or 8x8 to improve signal to noise N is up and E is to the left on the CCD monitor or in VF when CSHELL is mounted in its normal E W slit configuration The CCD has a 55 E W x 65 N S FOV 0 15 pi
137. tion with serial devices the CSHELL IC computer is equipped with a 4 COM Serial Port Adapter by STB Systems Inc 214 234 8750 The configuration of the serial board is as follows Port I O Base IRQ Comments COMI Ox3f8 IRQ4 Atttached to TC 1 COM2 Ox2f8 IRQ3 Attached to TC 2 COM3 0x3e8 IRQ10 Attached to Encoder COM4 unassigned Temperature Controller CSHELL uses two series 9620 Temperature Controller by Scientific Instruments Inc The controller communicates to the IC computer via the serial ports The TempCmd command allows you to communicate with the temperature controller using its native instructions outlined in its manual These instructions are summaried here for your convinence FUNCTION SYNTAX EXAMPLE Input the Setpoint Snnn S400 sets the setpoint to 40 0 Kelvin Input Proportional Term Pnn P50 sets the proportional term to 50 Input Integral Term Inn 120 sets the integral term to 20 Input Derivative Term Dnn D20 sets the derivative term to 20 Get Temperature Setpoint S S will return the Setpoint Get Proportional Term P P will return the proportional term Get Integral Term I T will return the integral term Get the Derivative Term D D will return the derivative term Get Heater Ouput H H will return the heater output Get Temperature T1 T T will return the T1 temperature Get Temperature T2 t t will return the T2 temperature Toggle Control Mode x X will toggle the heater off on Please note that the
138. tiply every pixel in buffer 2 by 100 and place the results in buffer 2 When you are done forming your expression selecting the Math button to perform the operation To copy data from one buffer to another use the middle set of panel items First select the destination and source buffers Select the CopyBuf button to perform the transfer To clear a buffer data in the buffer identify the buffer by selecting a button to the right of the clear button then SELECT the Clear button to delete The rotate operation allows you to rotate the data to the left or right Select the desired buffer then press one of the rotate buttons to rotate in the desired direction The Hide button will cause the command frame to disappear from the computer s screen 8 16 94 Page 57 IRTF CSHELL User s Guide The Stats frame The stats command frame provides the means for you to view elementary statistical information on groups of pixels and calculate box photometry values a Stats Statistics for Canvas A Buffer 0 Frame Mean 476 7 hn Ma 10346 uar 180590 53 5TO 424 96 Object 5 key Object 5 ky Upper left X 31 Y 37 x 15 Y 38 Bow Size 10 by 9 10 by 9 Sum 58152 32424 25738 Bean B46 2 360 3 286 0 Variance 278648 25 6797 7 297951 41 Std Dew 52 8 82 45 545 85 Hum Mxels g0 g Mim Pireti ae e e sm Sm Canvas a B C D E OFF Set 5ky Hide Set SubArrays Guide Array 1 Array z2 Array 3 Figure 16 The St
139. tively the vf programs is accessible at HP on the IRTFs Sun workstation Practicing with this program before your run can greatly improve observer efficiency Your support scientist will usually go over the operation of CSHELL and help you take calibration lamp data at Hale Pohaku in the first afternoon of your run d Bring the following with you e Offset guide stars if required The offset guider has a field of view that is an annulus with inner radius 100 and outer radius 200 and it can reach V 12 mag in 1 second with no moon Note that the CSHELL on axis CCD camera permits guiding while integrating has a field of view of 60 and it can reach V 16 mag stars under typical conditions Contact your support scientist about using this camera to guide on visible objects e Slit rotation information CSHELL can be rotated 90 to a few degrees accuracy but the process takes up to half an hour 8 mm or 4 mm tapes It is recommended to bring one tape per night to permit backing up each night s data on a separate tape Bring enough tapes for enough copies of the entire data set We find the video grade tapes to be of insufficient quality bring data grade tapes B Instrument Description CSHELL is a long slit spectrograph which uses a 31 6 lines mm 63 5 echelle with narrow band circular variable filters that isolate a single order orders from 11 to 56 The spectrograph can achieve resolving powers up to 42000 or 7 km s over the 1
140. tput are given in SIIL D Which calibration lines should you observe The purpose of the lines is to determine the wavelength zero point and dispersion for each observational wavelength grating position In practice one should observe a single calibration line for each desired wavelength as well as several lines distributed across many columns of the array for at least one wavelength setting at the start of each night The single line at each grating position selected wavelength directly allows the determination of the wavelength of the illuminated array column and observing several lines over a range of columns on the array allows the determination of the dispersion at that grating setting It is best to observe at least 3 lines which span at least half of the array 128 columns We wish to observe these lines at the same grating position used for the object observation wavelength so we must select the proper CVF wavelength for each line see Cal_lines Table III D without moving the grating This is done by entering the new CVF wavelength into the proper text field of the Observing Parameters Frame The calibration lines must also be sufficiently bright to observe in a reasonable amount of time e g 60 seconds Line intensities can be looked up in the copy of the elemental spectral atlas by M Outred kept with the CSHELL documentation at the telescope Lines must be looked up within each element s listing by wave number the atlas gives air
141. tring used in creating the file list on the Edit and Executed File window in the XUI program This command can only be executed from the XUI program Prompt DoFileMask on the Execute Do Files window Range Any string Initial j Syntax DOFILEMASK string DoPath This path identifies the subdirectory where the XUI program will search for DO or macro files The HOME and DATE macros are supported This command can only be executed from the XUI program Prompt DoPath on the Execute Do Files window Range Any legal UNIX subdirectory Initial HOME macro camxui Syntax DOPATH string DSPResetMSec Specifies the amount of time in millisecond between array reset Array resets are performed during idle periods Prompt DSP Reset Msec on the observing parameter s Eng page Range 500 to 10000 milliseconds Initial 1000 Syntax DSPRESECMSEC num DSPSampleMode Specifies the sampling mode used to readout the array during a GO Prompt Sample Mode on the observing parameter s Eng page Range Single A single sample is done by reseting the array After the integration time has passed the array is readout to produce an image Double After an array reset a pedestal image is readout After the intergration time a sample image is readout The final image is the result of the sample minus the pedestal readout Double DSPSAMPLEMODE single Double Initial Syntax DTime Specifies the dead time after a beam
142. ts of the line of pixels used to construct the XLineCut graph Range When autoscale is off these values define the scale on the data axis Print XCut Select this button to produce a hardcopy of the graph The Noise display is an engineering tool to display statistic on a group of pixels organized by columns The mod parameter would indicate the number of output in the system The min max mean and standard deviation could then be displayed for each output Graph 1 display the Min Max and Mean of the pixels The I bar shows the min and max while the point represents the mean pixel value Graph2 display the standard deviation for each mod Display Noise Buffer bo Mod 1 256 4 AutoScale Off On Area all Box Graphi Range 0 to 65000 Graph2 Range 0 to 500 Print Noise Graph 4 Figure 13 Noise display amp panel items Mod control how columns are group together For example 4 would group every 4th colmun giving stats on 4 different groups of pixels 8 16 94 Page 53 IRTF CSHELL User s Guide Area This control allow you to indicate the pixels used in creating the graph You may use the entire image All or just the pixel specified by the ObjBox Box AutoScale The Y axis is automatically scaled when on or scaled using the range values when off Graph1 Range When autoscale is off these values define the Y scale for the Min Max Mean graph Graph2 Range When autoscale is off these values
143. tz envelopes absorb much of the radiation long ward of 3 4 um lines in the above table with wavelengths greater than 3 um are difficult to detect due to this absorption as well as thermal emission by the envelopes An auxiliary program cal_lines is used to determine which calibration lamp lines are to be used at a given wavelength selected for observation The narrow spectral range of CSHELL usually prevents observing a calibration lamp in the same order as your object spectra and cal_lines determines which order the lamp lines must be observed in Position the mouse pointer in a UNIX text window on the Sun XUI computer selecting it with the left button and bringing it forward if necessary Type the following command in this window to display a list of calibration lamp lines which can fall on the InSb array when the grating is positioned for observing your astronomical line cal_lines A um more where A um is the desired central wavelength on the array The list of available lines can be scrolled through by pressing the space bar on the keyboard Alternately this list can be printed by the laser printer with the following command in the UNIX window cal_lines A um lpr These commands are also available on IRTF the workstation at H P One can print calibration line lists at H P by specifying the name of the H P laser printer uh88pr 8 16 94 Page 80 IRTF CSHELL User s Guide cal_lines A um lpr Puh88pr Now consi
144. u must position your object on the slit once you have found it in the imaging field 30 on each side This is easily done by displaying the field in a pane of the VF program and selecting the TCS Coordinates item from the VF Option menu Be sure that the plate scale slit rotation angle and slit position are correct then click the left mouse button while the pointer is at the center of your object Next press the F key on the Sun keyboard to enter the mouse coordinates and click on the Calculate Offset button to calculate how far to offset the telescope Then offset the telescope by pressing the Offset TCS button It is a good idea to acquire a frame at the new telescope position to ensure that your object will be on the slit Once this frame is acquired and saved if desired you should switch to your desired slit size and select spectroscopic observing mode removing the direct imaging mirror Spectroscopy It is best to move the telescope in the direction of the slit to position your object away from the array center and nod about half a slit length in the opposite direction in order to observe your source in both A and B beam positions For example if the slit is oriented East West default orientation then you may wish to move the telescope 7 5 east and use a 15 West nod between frames if you are observing a point source This would position your source spectrum nearly equally displaced from the array center in both the on and
145. uch as switching to the imaging mode and back to the spectroscopic mode setting up to peak up setting up to observe etc These repetitive tasks can be put into an cshellxui command file and executed thus saving time More than saving typing these command files can prevent loss of data by not having an important parameter set properly like turning on auto save See the CSHELLXUI and VF software guides III A for more information on using command files EXAMPLE The following command files switch between imaging and spectroscopic modes and set the detector bias appropriately They are the default image and spect macros image spect PVoltages 3 700 3 200 PVoltages 3 700 3 375 ITIME 0 1 InstMode S Cycles 1 Slit 1 0 Coadd 10 ITIME 10 InstMode D Coadd 1 Slit Open Cycles 20 AutoSaveXUI Off AutoSaveXUI On 8 16 94 Page 76 IRTF CSHELL User s Guide Other commands may be included in command files such as a Go command to actually start a sequence of exposures The most commonly used command files image spect goflat and godark are in the directory cshell macro cshellxui These files configure CSHELL to take images take spectra take flats and take dark frames respectively The goflat and godark files contain a Go command so they actually start a sequence of exposures once they are executed Be sure to review the contents of a command file by Loading it before execution to make sure that it configures CSHELL properly
146. use the user interface software Users must use a mouse windows and icons on the Sun computer to acquire and look at CSHELL data The IRTF staff has endeavored to make the user interface programs as intuitive as possible and they are fully documented in III A Using the programs can be frustrating however if one is not familiar with the Open Windows mouse button conventions Briefly the left mouse button is used for selecting items such as text fields buttons in windows and default menu choices The right mouse button is used to display a menu of choices by clicking it when the mouse is positioned on any object that displays a small down pointing triangle indicative of further choices A menu of options appears once this is done and menu items are selected by again pressing the right mouse button when the mouse pointer is positioned on top of them Default menu items are circled by ovals they can be selected by either the above procedure or else by just clicking the left button when the mouse pointer is over the original object associated with the menu Text can be selected with the left button in several ways The mouse pointer can be positioned at the desired insertion point and the left mouse button clicked to select that point for text insertion This selected position will be the active insertion point whenever the mouse pointer is positioned in the parent window of that text field Alternatively the mouse pointer can be positioned in a tex
147. utput lists the central vacuum wavelength and wave number as well as the corresponding grating order for the astronomical line The ensuing table lists the wave number actual wavelength apparent wavelength grating order CVF order sorting filter central wavelength and approximate SBRC array column of each calibration lamp line Note that no lines in the above example list fall in the same order 26 as the desired astronomical spectrum We can observe lines in other orders by simply changing the CVF wavelength as explained in SILA 8 16 94 Page 81 IRTF CSHELL User s Guide E IRTF Computer Services 1 IRTF Mauna Kea Computer Facilities The current IRTF computer facilities on Mauna Kea include a Sun workstation several PCs and a PostScript laser printer on an ethernet network at the summit These machines are also on a summit network that includes other Mauna Kea telescopes and the machines at Hale Pohaku Currently the IRTF has a Sun workstation at Hale Pohaku that is available for data archiving reduction etc during your run These machines on the summit network are only reachable through U H Manoa machines via Internet so you must make arrangements with your support astronomer if you need access to them before or after your CSHELL observing run You should obtain a guest observer account when you arrive at Hale Pohaku by logging into the IRTF workstation as guests Use this account for all activities while at the IRTF It will e
148. val is once every 5 Range OFF or ON Initial OFF Syntax TEMPRECORD off on VCCD Selects the position for the visible CCD dichroic Netural Density filter assembly Prompt Click on the VCCD Icon on the observing parameters window Range Out VCCD Dichroic and ND filter out of light path In Places the VCCD Dichroic and ND filter in light path Initial Out Syntax VCCD out in VCCDInit The command to initialize the visible CCD dichroic Netural Density filter assembly Syntax VCCDINIT VF Commands VF from the XUI program This command can only be executed from the XUI program Range Any legal VF command See the Command Dictionary for the VF program for syntax Syntax VF command Wait Sets the acquire or Go task busy for a time interval specified seconds Range 0 1 to 60 0 seconds Initial N A Syntax WAIT sec Wavelength This command changes the value of the CVFWlen and GWLen It is provide to allow the use to change the grating and CVF wavelenght with a single command Prompt WaveLen on the Parameters window Observing Page Range 1 10 to 2 449 2 46 to 5 60 microns Syntax WAVELEN num XUIHostName The IC program uses this hostname when initiating network communication to the XUI program i Range Enter the hostname of the workstation minutes running the XUI interface Prompt TempRecord on the Observing parameter s Initial Planck Eng page Syntax XUIHOSTNAME name 8 16 94 Page 42 IRTF CSHELL
149. ve them forward as well backward in order to isolate the failure Beware that filter wheel A is labeled wheel 1 and filter wheel B is labeled wheel 2 on the CSHELL dewar See Figure 1 in the CSHELL Hardware Description Appendix B for positions of the various filters on each wheel also see the CSHELL Filters notebook and see Figure 2 in the CSHELL Hardware Description Appendix B for positions of the slit wheel The conversions between wavelength and step position are given for each CVF in the following table 8 16 94 Page 101 IRTF CSHELL User s Guide CSHELL CVF Position Table CVE Wavelength Range ACVFI1 1 10 1 57 um BCVFI1 1 33 2 50 um BCVF2 2 46 4 54 um BCVF3 4 27 5 60 um Wavelengths Used 1 10 1 569 um 1 57 2 449 um 2 46 4 35 um 4 35 5 60 um Motor Position Equation 13495 61 A um 10609 83 1 480 02 um 2838 225 A um 1625 656 1570 229 A um 1674 65 um 6 22061 1 16178 x 107 Other Problems CSHELL can experience other problems also The following table lists some possible problems and suggested remedies Symptom Array or Cold box Temperature is wrong No Calibration Lamp lines IR Array Data Values are Funny or near zero Excessive or Intermittent Noise Solution Manual Sect Check dewar for liquid nitrogen make sure closed cycle cooler is on check controllers ILA Appendix D Check cshellxui status window check filter wheel positions in
150. vements shift the color map Dragging the cursor and pressing the The dragging motion rubberbands a group of pixels These pixels are adjust middle mouse button known as the Object Box Dragging the cursor pressing the adjust Draws a line from he starting pixel until the dragging motion is middle button amp holding down the completed The end points of this line is copy to the From and To shift key prompts in the TCS coordinates frame Pressing the select left mouse button Center the Object Box at the cursor s x y location Press F or T in the image display If the current active canvas is display an image pressing F or T will update the From or To coordinates in the TCS coordinates frame Press L in the image display If the current active canvas is displaying a linecut from the same buffer as the image pressing L will set a new X Y axis for the line cut Table A Description of Canvas Events 8 16 94 Page 48 IRTF CSHELL User s Guide The Main Panel The main panel contains buttons prompts and menu items to control the display type and their options For each canvas there is a main panel as shown below Selecting the Display menu gives the following options Image SpectraA SpectraB Header Histogram LineCut and XLineCut ee Cmd ColorMap gray cm a D Inverse ColorMap Display Image Buffer T ba Scale Fixed Auto Range 0 to 15000 zoom x1 x2 x4 xe gt Offs
151. ving and is placed in the fits header Prompt Object on the observing parameter s Obs page Range Any string up to 40 characters Initial Name of Object Syntax OBJECT string Observer This information identifies the observers and is placed in the fits header the A beam and a object frame is taken Then the telescope is positioned a the B beam and a sky frame is taken 4 Noise Image This is a special mode used to produce noise images For each cycle a image is readout Using these images the standard deviation of each pixel is calculated A frame is produced where each pixel position contains the standard deviation of that pixel position These value are multipled by 100 to preserve decimal information Initial 0 Syntax OBSMODE num Order Set the user s order The grating wavelenght is calculated based on the grating angle step position and an implied order This implied order is called the user s order Normal the user s order is set to the optimum order for a given wavelenght This command allows you to change the user s order Prompt None Enter command at prompt Range 8 to 60 Initial Optimum order Syntax ORDER num PVoltage Sets the user programmable voltage s VDDUC and VDET on the clock bias board i l Prompt The observing parameter s Setup page Prompt Observer on the observing parameter s Obs contains prompts for set the voltages First page input the appropriate values in VDDUC and Range
152. wavelengths and we use vacuum ones and we find that lines with intensities of 100 units or above can be adequately observed in 60 seconds or less Most lines listed by ca1_ lines can be observed in 15 s or less If you are observing in order n and the calibration line wavelength appears in some column in order ni then Aops the wavelength of that column in the astronomical spectrum order npp is obs gt robs M ni Nobs obs iS given in column 3 and ni is given in column 4 of the Cal_lines Table see also III D The expected position of a line on the SBRC 256 x 256 array is listed in col SBRC256 in the table The dispersion at one grating position is related to that at another position by rel c um where C is a different constant for each detector array and is the grating angle at each desired observational wavelength The grating angle can be found in the cshellxui window and it is also recorded in the FITS file headers see III F We recommend that you measure the zero point for all observed wavelengths and the dispersion for at least one wavelength each night of your run 8 16 94 Page 16 IRTF CSHELL User s Guide It is also a good idea to look at the CSHELL Atmospheric Atlas kept at the telescope kindly provided by John Lacy UT or the KPNO Solar Spectral Atlas Livingston W and Wallace L An Atlas of the Solar Spectrum from 1850 9000 cm I 1 1 to 5 4 um NSO Technical Report 91
153. witched in front of the CCD for observing bright objects VCCD icon in CSHELLXUI Pixels can be binned in software 1x1 2x2 4x4 or 8x8 to improve signal to noise N is up and E is to the left on the CCD monitor or in VF when CSHELL is mounted in its normal E W slit configuration The CCD has a 55 E W x 65 N S FOV 0 15 pixel plate scale and V 17 mag limit CCD images can be automatically sent to VF for display by selecting the View IC Data checkbox Once in VF they can be saved as FITS files via the VF Save Data menu choice It takes several seconds to send each frame to VF so continuous readout mode will slow considerably if this option is selected The guider should be operated as follows 1 The TO should start the gic program on max at the start of each night The observer should not start the gic Starting the gic is done by logging into casspc with the login guider no password Then type gic and a carriage return to start the gic 2 The observer should start the Guider XUI software by selecting Guider XUI from the CSHELL OpenWindows menu whenever he wishes to take images with the CCD for guider acquisition He should optimize exposure time set the proper binning e g 2x2 or 4x4 for better sensitivity in bad seeing or 8x8 to be able to guide on Jupiter s or Saturn s large disk select the 1000x CCD filter if needed Cshell XUD return the software to Single Shot frame mode and then QUIT the Guider XUI before ask
154. xel plate scale and V 15 mag limit CCD frames may be viewed in VF and saved as FITS files The CCD looks through an IR reflecting dichroic which has a bandpass similar to an R band filter HI Startup and Shutdown Software Notes All software can be started up from your user account on an IRTF Sun workstation at the summit planck or HP wien Just remember to type xuihostname wien in the command line of the CSHELL XUI program if running from that HP workstation The CSHELL and CASSPC the guider pc Instrument control IC Intel architecture computers can also be logged into from their directly connected keyboard monitor consoles The new calibration lamp program is called cal_lines which should be typed in from a UNIX prompt A CSHELL Startup 0 Turn on CSHELL boxes 2 5 in numerical order 1 Log into your Guest Account 2 Type openwin and lt CR gt at the UNIX prompt 3 Hold down the right mouse button on the blue desktop 4 If the IC program is not already running ASK a T O or Support Astronomer Either i Select Start CSHELL IC Software from the CSHELL menu or ii Log into CSHELL IC console as cshellic 5 Select Cshell XUI from the CSHELL menu 6 Select VF from the CSHELL menu 7 Turn on the CSHELL Array Power Supplies 8 Set Programmable Voltages in Setup Parameters XUI window B CSHELL Shutdown 1 Quit VF 2 Move Shutter Slit and Filter to Blank Position Spectroscopic mode turn lamps off 3
155. xpire 3 days after your run 2 Archiving Your Data The recommended data archiving procedure is to copy each night s data files onto a separate 4 mm or 8 mm tape Additionally we recommend that you archive the data from all nights of your run onto a single tape if you have time at the end of your last night This will ensure redundancy of your data in case some of your tapes are unreadable at your home institution Our current housekeeping procedure is to keep data on the Sun computer s herschel ifa hawaii edu disk for 1 week then compress the data UNIX format and retain it for another week before erasing it Be sure to read your data tapes as soon as you get back to your institution your data will be completely erased from our computer two weeks from the date it was taken Be sure to bring plenty of tapes at least 1 per night 1 for your run We use the UNIX tar command Tape ARchive to transfer CSHELL data onto the tapes Data are stored in FITS format and are readable by IRAF The following procedures for data archiving listing tape contents and restoring tapes require that you issue their proper UNIX commands from the Sun console or other UNIX window The 8 mm tape drive is located adjacent to the IRTF workstation named wien at Hale Pohaku so 8 mm tapes must be written from Hale Pohaku Wien s UNIX device name for the 8 mm tape drive is dev rstO or dev nrst0 The 4 mm tape drive is located adjacent to the IRTF summit workstation na
156. y 120 240 seconds per frame to be sure that the telescope is tracking and guiding properly The telescope operator can alter the tracking rates to correct for consistent drifts You must select the CVF Blocker Option and also use the shutter wheel blocker SPF when observing with the 1 1 1 57 um CVF This CVF transmits gt 2 5 um radiation causing significantly increased background in your data if not blocked as prescribed The blockers impart about a 10 reduction in flux over the 1 1 1 6 um region You must observe celestial standard stars to correct for telluric absorption Find a bright V lt 6 standard from either the Yale Bright Star Catalog or the IRTF standard tables Be sure that the star is of a satisfactory spectral type so that it does not contain any spectral features that you are attempting to observe in your objects You need to observe standards at a minimum of two different airmasses to be able to fit their telluric corrections to the airmass range of your objects Also try to observe the standards at the same array location row as your objects this will minimize CVF fringing in your data as well as simplify both your quick look and final data reductions The SBRC InSb detector saturates at different count levels depending on its bias voltage see table below try to keep your data values below the 1 linearity deviation for your selected bias Using a single fixed bias as done with the old NICMOS array is inappropriate

Users Manual - NASA Infrared Telescope Facility

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