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1. 4000 1000 Position 1000 1000 Position B00 600 Pixel value 400 200 ad S o Soo 1000 Position c gt 1500 2000 Soo 41400 300 200 Pixel value 100 0 1 000 Position N O O 0 Figure 18 Calibration lines measured with the LS150 0 25 slit for the 210zJHK grating Ar is represented in black Xe green and Ne red when available From top t bottom z Band J band H band amp K band LUCIFER User Manual Issue 1 1 41 7 Observing with LUCIFER The normal observing operation with LUCIFER is entirely performed through scripts Sect 7 3 g The interactive observing mode Sect 7 2 is described in detail here since it allows to introduce the definition of all parameters needed for scripts 7 1 Login and Software Start Usually the Lucifer control software LCSP is running continuously on the SUN V880 workstation That means the observer has only to start the necessary GUls Therefore he she has to use the dedicated LBTO linux machine and open a NXClient connection with the following parameters e User name observer e Password provided at the LBT e host sun luci After being connected to the SUN X environment double click on the Start LUCIFER icon on the desktop This will open all the necessary GUls for the observations The readout
2. 3902 ED046 1 169 2 2 1 2 2 2 3 2 4 Wavelength um Figure 26 Filter curves for broad band filters J filter 0 g o A n o 0 A E n S 9 0 a 0 al 1 1 1 2 13 1 4 dL Wavelength um K filter 0 S fe A n a 0 A E n g f 2 0 0 1 9 2 pe 2 2 2 3 2 4 2 5 Wavelength um Order Seperation Filter ED763 1 1 00 ED763 2 0 80 g fe A n a 0 60 A E n S o 0 40 in 0 20 0 00 1 20 1 40 1 60 1 80 2 00 2 20 2 40 2 60 2 80 Wavelength um Red filters installed in LUCIFER1 LUCIFER User Manual Issue 1 1 63 C 1 2 Narrow Band Transmission Transmission Transmission 4 2 Brackett y filter ED477 1 ED477 2 2 14 215 2 16 217 2 18 2 19 2 20 Wavelength um H2 filter ED469 1 ED469 2 Wavelength um J low and J high filter 00 80 60 o o 00 1 00 1 10 1 20 1 30 1 40 1 50 Wavelength pm Transmission Transmission Transmission Fell filter ED468 1 ED468 2 1 62 1 63 1 64 1 65 1 66 1 67 Wavelength um Hel filter HeI 1085 15 00 80 60 40 20 00 1 05 1 06 1 07 1 08 1 09 1 10 Ye 11 Wavelength um OH hole filter 1 00 1 05 1 10 1 15 1 20 1 25 Wavelength um Figure 27 Narrow band filter curves Part 1 64 Issue 1 1 LUCIFER User Manual Paschen filter Paschen y filter ED476 1 ED467 2 1 ED476 3 1 ED467 4 0 0 g g o 3 A A n n
3. e Instrument set_up This is now solved and END_OBSERVING_SETUP is now In the filter parameter two filters can be set Use this option to put crossed filters for acquisition on bright objects Two filters from the same filter wheel cannot be set together Possible crossed filters combinations for acquisition Hel z for a 7 mag extinction OH_1060 z for a 3 9 mag extinction Hel J for a 2 35 mag extinction and P_gam J fora 0 8 mag extinction Of course set_up like Br_gam Ks are possible but provide a much lower extinction factor The flexure compensation flag should in principle always be set to on For short photo metric standard or telluric stars observations this can be left to off e Telescope set_up LUCIFER User Manual Issue 1 1 51 Presets in active mode request that you provide a guide star otherwise the preset will fail Presets in track mode do not require a guide star but for the case no guide star information is present in the telescope set_up buffer e g at the beginning of the night provide as guide star coordinates the coord of your target A track mode preset will park the probe but the telescope software is anyway awaiting a full list of parameters including the guide star information e READOUT set_up NDIT is the number of reads DIT that will be performed at a given position For NDIT gt 1 the SAVE MODE must be integrated If you want to save more than one
4. Camera Panel The camera wheel panel allows the camera selection The N3 75 camera is for imaging and the N1 8 meant for spectroscopy Note the N30 camera has been designed for observations together with adaptive optics and is currently not installed Note If moving from one camera to the other you notice the field is not centered again it is most probably because the camera wheel did not reach its position properly In this case simply move to another camera and then back If needed ask your LBTO support astronomer to re initialise the camera wheel from the corresponding engineering panel to which you do not have access as user Grating Panel From the grating unit panel the mirror position for imaging and three different gratings can be chosen Furthermore the current wavelength is shown and the text field Desired Wavelength allows user input for new wavelength The unit is in microns and the maximum meaningful precision is 0 1nm The desired grating has to be specified before the wavelength is typed in since 44 Issue 1 1 LUCIFER User Manual the wavelength value is cleared when a new grating unit position is selected After typing in a new wavelength the user has to click the SET WAVELENGTH button and of course the COMMIT button to execute the setup change When no wavelength i given the selected grating is moved into position but it will not be tilted to a defined angle Use this option only when the desired grating is fixed mache
5. Darks daily for the readout modes used Note Darks with exposure time DITxNDIT less than 1 minute can be taken with the dome dark and the two blind filters For higher exposure time darks the blind mask has to be put in the focal plane This has the advantage to allow dome lights to be turned on The only internal calibration which absolutely needs to be taken with no light in the dome is the spectroscopic flatfield for which the calibration unit is needed Although arcs could be taken with 38 Issue 1 1 LUCIFER User Manual Table 17 Arc lines count rate per second The integration time are for each lamp separately but they of course can be switched together The counts are given for the brightest B lines and the average of the other typical fainter lines T N1 80 camera N3 75 camera Slit Integration counts Integration counts time sec B T line time sec B T line 210_zJHK grating z Band Recommended lamps Ar Xe S150 2 2 3000 1500 2 2 750 400 S300 2 2 4000 2000 2 2 1000 500 S450 S600 2 2 12000 6000 2 2 3000 1500 SpecPhot 2 2 15000 7500 2 2 3500 1800 J Band Recommended lamps Ar Ne S150 10 10 1500 300 30 30 1200 250 S300 10 10 2000 400 30 30 1500 300 S450 S600 10 10 6000 1200 10 10 1500 300 SpecP hot 10 10 7000 1400 10 10 1700 350 H Band Recommended lamps Ar Xe S150 30 30 4000 200 120 120 4000 200 5300 30 30 500
6. FS6 with the 210_zJHK grating and the N3 75 camera unlike all other measurements 34 Issue 1 1 LUCIFER User Manual Wavelength Angstrom 21345 1 Figure 15 Sky line spectrum measured with the 1 slit the 210 ZJHK grating and the N1 8 camera at different airmass of 341 degrees and the guide probe parked You fix your integration time and let the sky luminosity variation do its jobs Good flats are taken of course only under clear sky conditions A minimum of 5 frames taken over a range of 3000 17000 ADUs provides a good minimal set of data to derive a flat field Because of the relatively small pixel scale of LUCIFER sky flats in narrow bands have to be started before sunset Start integrating in K narrow band filters Br_gam amp H2 35 minutes before sunset After that Fell can be started followed by P_gam amp P beta Once this is finished you enter the very short time scale period where all broad band filters can be taken starting with the red filters K Ks and ending with the blue ones z When taking morning twilight flats the order of the filters to be used is of course reversed short wavelength first long wavelength 24m last It is im
7. The operation is then repeated with the other auxiliary cryostat the one containing the new set of masks After the exchange at least one auxiliary cryostat has to be warmed up to remove the cabinet it contains and receive new masks There is thus a minimum of a week between 2 cabinet exchanges At the moment cabinet exchange are foreseen once per month with the goal before each new block of science runs A software tool the LUCIFER Mask Simulator LMS has been made available to prepare masks for multi objects spectroscopy and is presented in section Permanent masks A set of masks is permanently installed in LUCIFER These masks are meant either for instrumental calibration or long slit spectroscopy These include some sieve masks used essentially to measure flexures and internal field distortion a blind mask to take dark frames a set of long slits and a mask thought for spectrophotometric calibrations These masks all have a fix mask ID which is indicated in the Table 3 as well as the current position of these masks in the mask s cabinet 3 1 3 Collimator The refractive collimator with a focal length of 1500 mm is used in all modes The resulting collimated beam size is 102 mm The collimator includes 4 flat folding mirrors The last of those mirrors is motor driven and used for the instrument internal flexure compensation LUCIFER User Manual Issue 1 1 13 Table 3 Permanently installed masks Mask Name Mask ID Position in
8. focal plane unit sensor 3 getter unit sensor 4 structure top sensor 5 camera unit sensor 6 grating unit sensor 7 MOS unit sensor 8 MOS unit position of mirror 4 motor 1 position of mirror 4 motor 2 position of camera unit camera name arcsec pixel detector focus steps from reference position of FWi name of filter in FWi position of FW2 name of filter in FW2 position of the grating unit name of the grating unit element tilt voltage central wavelength microns used grating diffraction order regulation loop status position of the MOS unit number of the used mask ID of the used mask description of the used mask position of pupil viewer 60 Issue 1 1 LUCIFER User Manual B Grating Efficiencies Sth Order 4th Order 3rd Order 2nd Order Efficiency 0 8 1 L 2 1 4 1 6 1 8 2 2 52 2 4 Wavelength um Figure 24 The efficiency of the 210zJHK grating versus the wavelength in Littrow configuration The different orders 5th 2nd of the grating are color coded H K grating with 200 lines mm Ks grating with 150 lines mm 0 9 0 9 2nd Order 0 8 0 8 0 7 0 7 0 6 0 6 gt gt E E o 0 5 o 0 5 A HA A q 0 4 2 0 4 H H l l 0 3 0 3 0 2 0 2 0 1 0 1 LA 0 0 0 0 0 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 254 0 8 1 0 1 2 1 4 1 6 1 8 2 0 Died 2 4 Wavelength um Wavelength um Figure 25 Grating efficiency versus wavelength in Littrow configuration 200 H K grating left 150_Ks right LUCI
9. telescope temp at sensor 205 TTEMP206 8 911000 telescope temp at sensor 206 TTEMP207 8 722000 telescope temp at sensor 207 TTEMP208 8 428000 telescope temp at sensor 208 TTEMP209 8 889000 telescope temp at sensor 209 TTEMP210 8 628000 telescope temp at sensor 210 TTEMP301 8 896000 telescope temp at sensor 301 TTEMP302 7 168000 telescope temp at sensor 302 TTEMP303 8 686000 telescope temp at sensor 303 TTEMP304 7 555000 telescope temp at sensor 304 TTEMP305 8 238000 telescope temp at sensor 305 TTEMP306 6 566000 telescope temp at sensor 306 TTEMP307 8 711000 telescope temp at sensor 307 TTEMP308 7 188000 telescope temp at sensor 308 TTEMP309 8 645000 telescope temp at sensor 309 TTEMP310 6 682000 telescope temp at sensor 310 SMTTEMP 6 100000 ambient temp SMT weather station SMTPRES 693 559900 pressure at SMT weather station SMTHUM 23 300000 humidity at SMT weather station SMTDWPT 13 350290 dewpoint at SMT weather station LBTTEMP 0 000000 ambient temp at LBT weather station LBTPRES 0 000000 pressure at LBT weather station LBTHUM 0 000000 humidity LBT weather station LBTDWPT 0 000000 dewpoint LBT weather station GUIRA 21 52 36 538 RA of guide object GUIDEC 02 25 52 21 DECS of guide object Information about the status of the calibration lamps STATLMP1 OFF Ne STATLMP2 OFF Ar STATLMP3 OFF Xe STATLMP4 OFF HALO1 STATLMP5 OFF H
10. 40 miles south of Tucson AZ o g Air transmittance Air Transmittance 1 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 4 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 4 Wavelength um Wavelength um a The air transmittance for Mauna Kea and three b The mean air transmittance for the site of 2MASS different water vapor levels 1 0mm red 1 6mm north Mt Hopkins which is located about 150km green 3 0mm blue ca 100 miles southwest of the LBT Figure 7 Transmittance vs wavelength for Mauna Kea a and Mt Hopkins b 4 2 Background Emission The near infrared sky spectrum measured from the ground at a typical observing site is shown in Fig 8 These lines are well known and can be used for wavelength calibration in spectroscopic mode Below 2 um the night sky emission is dominated by OH and O airglow emission Unfortunately the intensity varies about 5 10 due to changes in local density of OH over timescale of the order of 5 15 minutes Above 2 um thermal emission from the atmosphere and from the telescope dominates the background radiation 4 3 Imaging Jitter In classical NIR broad band imaging the signal of the sky background is much higher than the one from the objects Additionally it s intensity can vary considerably on timescales of minutes Jitter imaging takes care of that issue with a minimum loss of observing time For each exposure one observes the same region on the sky with different small offsets around a central po
11. 9 Basic characteristics of the LBT effective primary aperture Drel 8251 mm focal length fre 123421 4 mm effective system focal ratio Nra 15 0 primary spacing 14417 mm center to center image scale 0 59836 mm arcsec FOV 7 field curvature rra 1043 mm AO System Secondary Mirror The effective primary aperture of 8 251 meters in the table above is the area on the primary seen from the instrument because the slightly undersized secondary mirror is the pupil stop of the telescope optics The telescope focal length and image scale were determined by tying astrometric solutions on sky arcsec pixel to the scale of the precision sieve mask mm pixel in LUCIFER There is currently a rigid secondary mirror installed on the SX side used for seeing limited obser vations The first adaptive secondary mirror to be installed on the DX side is scheduled to enter operation in late 2010 5 2 Pointing amp Collimation The LBTO maintains models for both the pointing and collimation of the telescope the goal of which is to deliver to the wavefront sensor wfs a sufficiently collimated image that it can converge to a well collimated system in a few cycles The pointing model corrects for deviations of the real telescope from a perfect mechanical model such as a tilt of the azimuth axis off zenith or flexure of the telescope tube as a function of the elevation The collimation model corrects low order optical aberrations e g coma focu
12. The mean time needed for collimation requests 90 measurements was 135seconds A correction of the telescope pointing takes in average 7 minutes For spectroscopic observations one has to add the time needed to move the mask in out of the focal plane To move a mask from its cabinet storage position to the focal plane it typical takes 2 5 minutes Since however it is recommended to move the mask in the focal plane position while presetting the overhead quoted here represents only the time to move the mask from the turnout position to the focal plane 45seconds Table 10 summarizes all types of overheads Example of overhead calculation based on true examples without preset or acquisition time Imaging Detector mode DCR DIT 20 sec NDIT 3 NEXPO 1 20 offsets Total time needed 20 4 2 3 20 20 18 20 12 1920 seconds for 1200 seconds of on source integration 62 5 of shutter open time Spectroscopy Detector mode MER DIT 600 sec NDIT 1 NEXPO 1 5 offsets Total time needed 600 10 5 5 18 5 12 3200 seconds for 3000 seconds of on source integration 93 7 of shutter open time 6 4 Limiting magnitude amp recommended integration times 6 5 Sky emissivity Sky emissivity is an important parameter setting absolute upper limit for useable DITS in imaging mode Of course sky emissivity fluctuates a lot in case of clouds and is related to Moon illumination The blue
13. Wavelength nm Wavelength nm Figure 2 Transmission curve of the LUCIFER 1 entrance window The plot left shows the overall transmission inclusive the leak around 400nm while on the right a zoom over the NIR range is presented 3 1 2 Focal Plane amp Slit Masks The useful unvignetted field of the telescope is 7 The layout of the optics for the seeing limited case covers a field of 4 x 4 144mm x 144mm The focal plane improperly refered to the FPU Focal Plane Unit can be equipped with masks for long slit and multi object spectroscopy as well 12 Issue 1 1 LUCIFER User Manual as field stop mask Up to 33 masks are available inside the instrument out of which up to 23 can be exchanged without warming up the instrument The multi object mode of LUCIFER offers the possibility of obtaining spectra of several objects simultaneously The masks used for this mode are custom made laser cut masks The LUCIFER multi slit masks are made from 125 wm thick stainless steel from ThyssenKrupp chem ically blackened on one side The coating has been tested at LN2 temperature and in a laser cutting machine MPE supplies this material for the mask cutting machine at LBT The sheet thickness has been optimized for the LUCIFER mask frames No other m
14. image per position then set this with NEXPO which is the number of exposures of integration DIT XNDIT that wil be performed at the current position If you decide to have NDIT gt 1 and SAVE_MODE normal note that all your NDIT images will be saved individually but only at the end of the NDIT reads and will all have one and the same fitsheader The total number of frames you will get is defined as Number of offsets defined in Observing set_up NEXPO is you are in integrated mode with NDIT gt 1 or Number of offsets defined in Observing set_up NEXPO NDIT if data are saved in normal mode e Observing set_up After a spectroscopic acquisition the OFFSET_TYPE has to be relative otherwise you loose the centering of your object behind the mask There is not automatic return to origin position at the end of the scripts except you set your offsets accordingly The ACQUISITION command makes a read as defined in Readout set_up but does not save it This command is useful for spectroscopic acquisition since it pauses the script till you are satisfied to continue you are finished with your alignment jitter creates a random generated jitter pattern to take as defined in the example before 10 images 10 offsets separated by a maximum radial distance of 40 The syntax of the command is AX ARA arcseconds AY ADEC arcseconds APA degree The pointing command allows to make huge offsets but still
15. infrared standards is available at the telescope in the IRTC notebook and the corresponding stars are in a catalog on the LUCIFER computer TargetsCoord PerssonStars tab The stars to use are named BS91 These are well distributed over the sky so one should be reasonably near your first science target Once the telescope is collimated meaning that the rms wavefront error has converged to something below 400nm the collimation model will normally keep you close to decent collimation even on large slews of the telescope Difficulties can be found on nights with very poor seeing gt 3 arcsec very low winds lt 2 m s or large temperature swings The poor seeing affects collimation because the entrance aperture to the wfs is three arcsec in diameter so poor seeing makes it difficult to find the centroids in each subaperture Conversely very good seeing should yield rms wavefront errors well LUCIFER User Manual Issue 1 1 23 Current IE amp CA at pointing Final IE amp CA values IE 12 3 CA 27 8 IE 26 2 CA 32 6 Star centered at 1054 927 Star centered within few pixels Offset correction on center of rotation 1014 1043 4 8 x 13 92 y LUCIFER image LUCIFER image Figure 9 Illustration of the pointing correction method below 400nm Low wind speeds do not flush out the dome air so you can get dome seeing effects Effect of large temperature changes have already been discussed Low order coll
16. is completely governed by the guide stage accuracy of motion In repeated tests we achieve 50 mas rms in the X direction on LUCIFER and 30 mas in Y 5 4 Open loop tracking stability Please keep in mind that the telescope will deliver the best image quality under closed loop ACTIVE mode operations It is in your best interest to set up your observations with an appropriate off axis guide star The additional overheads of starting up the ACTIVE mode observations are small a few seconds compared to TRACK mode However it is possible and may be desireable to perform rapid observations in TRACK mode such as obtaining spectra of telluric standards where neither the precise positioning nor collimation is strictly necessary These objects are typically bright and only a few minutes are needed to take a pair of spectra In TRACK mode you are fully subject to any thermally induced drifts in the pointing so it is likely that you will need to at least make one coarse correction of the telescope position to place your target at the required location on the LUCIFER detector LUCIFER User Manual Issue 1 1 25 AGw Patrol Field AGw r theta stage theta limits AGw r theta stage radial limit The center of rotation is 612 5 mm above the Gregorian rotator center LUCIFER 4 Field of View Gregorian Focal Plane 11 diameter Su Figure 10 Plot of the AGw guide probe patrol field green is shown relative
17. n 0 n 0 d d E E n n E El o w u0 H 0 pa E 0 0 0 0 1 24 1 26 1 28 1 30 1 32 1 34 1 07 1 08 1 09 1 10 LT 1 12 Wavelength um Wavelength um Y filter 1 00 0 80 a o d n n 0 60 pS E n E 6 0 40 a 0 20 0 00 0 90 0 95 1 00 1 05 1 10 1 15 1 20 Wavelength pm Figure 28 Narrow band filter curves Part 2 If not otherwise specified the red curves are the filters present in LUCIFER1 When specified e g for Y1 Y2 then both filters are present in LUCIFER1 LUCIFER User Manual Issue 1 1 65 D Example of Scripts Template used for taking photometric standards Note the mask parameters were set from a previous use of this template and are simply commented out START_TELESCOPE_SETUP TARGET_NAME FS 106 TARGET_COORD 01 49 46 95 48 37 53 4 GUIDE_NAME GS_R13 91_d4 31_pos230 96 GUIDE_COORD 01 50 07 139 48 40 37 50 ROT_ANG 45 ROT_MODE position TELESCOPE_MODE active END_TELESCOPE_SETUP START_INSTRUMENT_SETUP CAMERA N3 75 FILTER K GRATING_UNIT mirror CENTRAL_WAVELENGTH HMASK NB4 MASK_POSITION mask_in_turnout FLEXURE_COMP 0FF END_INSTRUMENT_SETUP START_READOUT_SETUP DIT 2 NDIT 30 NEXPO 1 ROE_MODE 02dcr SAVE_MODE integrated SAVE_PATH data luci YYYYMMDD FILENAME luci_YYYYMMDD_Std_ END_READOUT_SETUP START_OBSERVING_SETUP COORD_SYS DETXY OFFSET_TYPE relative OFFSET 45 45 OFFSET 00 90 OFFSET 90 0 OFFSET 00 90 OFFSET
18. na na 1450 J na na 5500 H na na 7100 Ks na na 3500 K na na 4550 J low na na 2150 J_high na na 2150 Y1 na na 620 Y2 na na 750 0H_1060 na 2700 110 0H_1190 na 4450 190 Hel na 2150 180 P_gam na 3600 150 P_beta na 6200 na Fell na 11000 480 H2 na 8800 350 Br_gam na 8300 3200 N1 8 camera Flat fields Knowing the necessary integration time for a given calibration with the N1 8 N3 75 camera multiply divide it by 4 to find the required integration time for the N3 75 N1 8 camera for an equivalent signal to noise Some flatfield images may present a small ripple effect non exisiting in night sky data This ripple can easily be filtered out in e g the Fourier plane Table 16 present the count rate for spectroscopic flatfields When setting your calibrations script aim at a level of 10000 counts 15000 max Wavelength calibration Knowing the necessary integration time for a given calibration with the N1 8 N3 75 camera multiply divide it by 4 to find the required integration time for the N3 75 N1 8 camera for an equivalent signal to noise Table 17 present the count rate for calibration lamp lines as measured with the 210_zJHK grating in all 4 used orders and for different slits Two values are given the count rate of the brightest lines Especially over night you definitively want to avoid saturating them to avoid remanents effects The other value represents the average count rate as measured over the typica
19. nicely disappear in difference images however do not put an object in view of taking its spectrum perfectly in the middle of the detector in Y Figure 6 Part of a LUCIFER image where few features bad column line and few bad pixel clusters have been highlighted Note Unlike most infrared detectors the LUCIFER detector is read only upon request there is no permanent reads on going 3 3 Calibration Unit This unit can be moved in front of the entrance window Three arc lamps Neon Argon and Xenon are available for wavelength calibration and three halogen lamps for flat fields Note that moving the calibration unit in front of LUCIFER obstructs the light coming from the telescope thus guiding will not be able to continue while internal calibrations are being taken over night In this case ask the telescope operator to pause guiding and active optics corrections for you before the calibration unit is moved in the light path LUCIFER User Manual Issue 1 1 19 4 Observing in the NIR 4 1 Atmospheric Transmittance The water vapor in the atmosphere is the leading cause for absorbing light in the near infrared The transmission of light for three different water vapor levels in the wavelength range from 0 9 um to 2 5 um is shown in Figure 7 a This plot is a model atmosphere for Mauna Kea The plot 7 b shows the mean transmittance of an atmospheric model for the 2MASS site The location of 2MASS is on Mt Hopkins about 60 km
20. readout set up The two available readout modes can be selected with the ROEMode pull down menu There are three different options to save files Savemode pull down menu 1 normal for each exposure the detector is read out NDIT times for DIT seconds When the images are saved NDIT files are written each with DIT seconds exposure time This is repeated for the number of frames required 2 integrated only one frame is saved It corresponds to the sum of the DITXNDIT seconds of integration 3 cube data are saved in a cube with NDIT planes Filename root allows to set the root of filenames that should be written If the last character of this string is not a digit the GEIRS read out software will append four digits to this root automatically and write files with ascending numbers proven practice is to end the root of the file names with an underscore character Typically frames are called luci YYYYMMDD The Save Path text field can be used to determine a new saving directory This can be done by typing the new path directly into the text field or by using a file chooser which is opened when the button is pressed If the new save directory does not exist a message window appears after clicking the Set new values button to ask you to create this new directory Sending the new setup to the readout manager is done by clicking the Set new values button located directly below new r
21. remain in closed active loop since you have to provide the coordinates of a new guide star Note however that the position angle cannot be changed between the two pointing positions FLAT LAMP amp DARK are used for calibration purposes and should be set in separate scripts independant of the science script FLAT is used only to take skyflats It has to be set together with an instrument set up and a readout mode set_up NEXPO is used to define how many frames will be saved LAMP is used to take calibrations with the calibration unit The lamp needed arc or halogen has to be defined as well as the time the lamp should remain on The script automatically takes frames with first the lamp off data then the lamp on Currently you still have to define the time for which the lamp needs to be on This is defined as NEXPO NDIT DIT 2sec NDIT 1 5 where 2 sec is the readout time for the o2dcr mode lamp calibrations in mer mode are rare since the integration time has to be short and 5 the time to save a fitsfile If NDIT gt 1 the save mode has to be integrated DARK is used to take dark frames Should you wish to save darks in Normal or Integrated mode so should you set two scripts separately FLUSH DETECTOR performs 11 minutes of detector short reads It is recommended to use this between your dark scripts to clean the detector Similarly at the end of your dark script please run the clea
22. sky counts pixel sec 25007 oe TA T a 3007 T T gt T 5 2 0 F Why M ma J 2s i E h F Wi aia ih 20t Es 1 Hh a A a 1 05 4 E HI I WN ui NL d F i 10F f W 7 E A A AN E i h di t Ye JE BE l a PAL Y L hol CHAN FL 3 0 0L4 1 f f OE i fi f 1 5x10 1 6x10 1 7x10 1 8x10 1 5x10 1 6x10 1 7x10 1 8x10 Wavelength Angstroem Wavelength Angstroem J band signal object counts pixel sec J band signal sky counts pixel sec 0 877 7 15 r F 1 0 6 wi T samme dt a 1 04 ar M tt eal EN IMAN AT en call rh E ANY Yu 1 del j WW pemean ma 0 2F 4 W i LA fay b Y 0 0 Li ii 1 1 1 1 i 0 0 1 1 18x10f 20x10f 22x10f 24x10f 26x10f 28x10f 30x10 1 18x10f 20x10 22x10f ae 26x10f 28x10f 30x10 Wavelength Angstroem Wavelength Angstroem z band signal object counts pixel sec z band signal sky counts pixel sec JL oh E Ua 0 0L 1 fi 1 0 0 i 9 00x10 9 50x10 1 00x10 1 05x10 9 00x10 9 50x10 1 00x10 1 05x10 Wavelength Angstroem Wavelength Angstroem Figure 14 Stellar counts and sky counts in ADU second pixel for FS6 and FS29 measured with the 10 slit and all gratings Color code black FS29 with 200 H K grating and Order Separator blue FS29 with the 210_zJHK grating red FS29 with the 150_Ks grating and Ks filter violet FS6 with the 210 zJHK grating and green
23. the position angle does not make any difference the object will always move the same way on the detector Offset list 0 0 60 60 120 0 0 120 120 0 6 3 Overhead Calculations Each read is associated with a given readout time it is 2 seconds in DCR mode and 10 sec in MER mode Please note that an integration of 1 minute defined as 2 seconds x 30 NDIT will have a 50 duty cycle i e it will use 2 minutes of time to complete this 1 minute of on source integration LUCIFER User Manual Issue 1 1 29 Under good and smooth observing conditions it has been calculated that offsets in active mode guiding and sending active optics correction take in average 18 seconds while only 4 seconds when performing them in track mode Furthermore you have to add the time to create save the fits file This time is strongly related to the number of integrations requested and the mode in which data are to be saved The average time for this process is 12 seconds between 5 for single frames and 20 in practice To those times one has to add the preset time This time can be only the slewing time if one uses the track mode However most observations will be performed in guided mode with active optics correction on Therefore the guider acquisition and collimation times must be added Over the Sept Oct 2009 commissioning over 214 succesful preset mixed of telescope modes track z active the average preset time was of 70seconds
24. to the 4x4 LUCIFER field of view gray square and the delivered focal plane at the left front bent Gregorian focal station outer 11 arcmin diameter circle 26 Issue 1 1 LUCIFER User Manual 6 Preparing observations with LUCIFER 6 1 Available tools 6 1 1 Exposure Time Calculator ETC A LUCIFER exposure time calculator has been made available and can be reached at http www lsw uni heidelberg de lucifer cgi calculator calculator py It should be used to prepare your observations and estimate the needed integration time for your purpose 6 1 2 LUCIFER Mask Simulator LMS LMS is an observer support tool for the preparation of LUCIFER MOS mode observations The following is a short overview and by no means sufficient to run LMS Before using the program please read the LMS user manual carefully This software tool is used to 1 set the instrument configuration camera grating filter 2 set the default slit parameters slit type width length 3 select reference stars for telescope pointing and rotator angle offset correction 4 select guide stars for telescope guiding in one or more pointings 5 position MOS slits manually on a source image on the source centroid using a centering routine automatically on a target list LMS requires two input files e The ISF instrument summary file containing the relevant telescope and instrument parameters This file is part of the LMS package e A FITS image or s
25. 0 250 120 120 5000 250 5450 5S600 30 30 15000 750 30 30 3500 200 SpecPhot 30 30 17000 800 30430 4000 200 K Band Recommended lamps Ar Ne Xe S150 30 30 30 500 200 120 120 120 500 200 5300 30 30 30 600 250 120 120 120 600 250 5450 5600 30 30 30 1800 700 60 60 60 900 350 SpecPhot 30 30 30 2000 800 60 60 60 1000 400 200_H K grating OrderSep Recommended lamps Ar Xe S150 10 10 2000 300 20420 1000 150 300 10 10 3000 400 20 20 1500 200 5450 5S600 10 10 9000 1200 20 20 4500 600 SpecPhot 10 10 10000 1300 20 20 5000 700 150_Ks grating Ks Filter Recommended lamps Ar Xe Ne S150 10 10 10 800 150 30 30 30 600 100 S300 10 10 10 1000 200 30 30 30 750 150 S450 S600 10 10 10 3000 600 30 30 30 2300 600 SpecPhot 10 10 10 4000 700 30 30 30 2500 650 LUCIFER User Manual Issue 1 1 39 the dome lights on it is not recommended 1000 800 600 400 Pixel value ZOO 1 1 L 1 1 1 1 1 1000 1500 Position r gt 0 u 0 0 Sooo 4000 3000 Pixel value 2000 Toa all oa kadika ul 1000 1500 2000 Position c gt Figure 17 Calibration lines measured with the LS300 0 5 slit for the 150_Ks top and 200_H K bottom grating Ar is represented in black Xe green and Ne red when available From top t bottom z Band J band H band amp K band 40 Issue 1 1 LUCIFER User Manual 3000 2000 Pixel value p 0 0 0 JL A
26. 45 45 END_OBSERVING_SETUP Example of Jitter imaging template taking3 images per position NEXPO performing 10 offsets with a maximum offset size of 90 between positions START_INSTRUMENT_SETUP CAMERA N3 75 FILTER Ks GRATING_UNIT mirror MASK_POSITION no_mask_in_use END_INSTRUMENT_SETUP 66 Issue 1 1 LUCIFER User Manual START_TELESCOPE_SETUP TARGET_NAME TARGET_COORD GUIDE_NAME GUIDE_COORD ROT_ANG ROT_MODE TELESCOPE_MODE END_TELESCOPE_SETUP START_READOUT_SETUP DIT NDIT NEXPO ROE_MODE SAVE_MODE END_READOUT_SETUP START_OBSERVING_SETUP OFFSET_TYPE COORD_SYS JITTER END_OBSERVING_SETUP YourFavorite 00 11 22 33 33 44 55 66 SelectedGS 00 11 20 7 33 44 06 77 88 position active 02dcr NORMAL absolute DETXY 10 90 0 Example of spectroscopic scripts Acquisition template including blind offset START_INSTRUMENT_SETUP CAMERA FILTER GRATING_UNIT MASK MASK_POSITION FLEXURE_COMP END_INSTRUMENT_SETUP START_TELESCOPE_SETUP TARGET_NAME TARGET_COORD GUIDE_NAME GUIDE_COORD ROT_ANG ROT_MODE TELESCOPE_MODE END_TELESCOPE_SETUP START_READOUT_SETUP DIT NDIT NEXPO ROE_MODE SAVE_MODE END_READOUT_SETUP N3 75 Br_gam K mirror NB4 mask_in_turnout off MyTarget 11 22 33 44 55 00 7 GSC 11 22 32 9 44 55 01 2 12 5 position active o2dcr NORMAL LUCIFER User Manual Issue 1 1 67 S
27. ALO2 STATLMP6 OFF HALO3 Temperature of electronics racks RACKTEM1 292 82 rack sensor 1 I Rack RACKLVL1 100 0 output level channel 1 RACKTEM2 293 82 rack sensor 2 motion control electron RACKLVL2 100 0 output level channel 2 RACKTEM3 287 83 rack sensor 3 readout electronics RACKLVL3 100 0 output level channel 3 RACKTEM4 284 06 rack sensor 4 ambient RACKLVL4 200004 0 unused LUCIFER User Manual Issue 1 1 59 RACKCLG gt 0N Pressure and temperature of instrument PRESSUR1 PRESSUR2 DETTEMP1 DETTEMP2 HOW WOW HW HW WH Instrument set up M4M1POS M4M2P0S CAMPOS CAMNAME PIXSCALE INSFOCUS FILTPOS1 FILTER1 FILTPOS2 FILTER2 GRATPOS GRATNAME GRATVOLT GRATWLEN GRATORDE GRATLOOP MOSPOS MASKSLOT MASKID MASKNAME PVSTATUS LMS_INFO DATATYPE END 3 1200E 7 2 2300E 5 77 00 60 67 72 69 70 67 81 74 505 H o e Le o HR Aaron nn 00 NA AX AX 5 sos o o 1313 367 2 N3 75 Camera 0 12000 165 3 gt clear 14 7K 2 mirror 3 85069 not used not used OPEN no mask in use unknown unknown unknown gt PUPIL_VIEWER_OUT No LMS information gt SCIENCE cooling of the electronics rack mbar mbar input channel A detector input channel B cold bench sensor 1 structure bottom sensor 2
28. DE Here the telescope mode can be set to 1 STATIC 2 TRACK Only telescope tracking is running 3 GUIDE Tracking and guiding is running without active optics 4 ADAPTIVE 5 ACTIVE The full package for normal observing Tracking guiding active optics All three input sub panels Next Target Next Guide Star Next Telescope Setup have to be activated by clicking the corresponding SET TARGET SET GUIDE STAR SET TELESCOPE button When the input is okay the button will change to green After all three are green the ComMIT TELESCOPE SETUP button can be pressed The bottom right part of the panel allows you to set the wait for collimation flag This has to always be on then scripts will start integrations after the collimation is successful otherwise integrations may start just after guiding started and independantly of the telescope delivered image quality Should a preset be successful but the active optics not starting or not collimating change this flag to OFF so the telescope preset finishes Then you can preset again do not forget to reset the flag to ON again LUCIFER User Manual Issue 1 1 47 ReadoutManagerGul Readout Control me e o Exposure 0 Free space MS 44185 MB free Last file luci 20091117 0001 fits Save image manual y Saveimage Next file luci 20091117 0002 Frame type SCIENCE B Object unknown Current Readout Setup New Readout Setup DIT 1 98 ROEMode o2dcr DIT 1 98 ROEMod
29. DE normal SAVE_PATH data luci YYYYMMDD FILENAME luci_YYYYMMDD_Flat_ END_READOUT_SETUP START_OBSERVING_SETUP FLAT END_OBSERVING_SETUP Examples of script to take dark calibrations in the morning START_READOUT_SETUP DIT 2 NDIT 1 NEXPO 5 ROE_MODE 02dcr SAVE_MODE normal SAVE_PATH data luci 20091104 FILENAME luci_YYYYMMDD_Dark_ END_READOUT_SETUP START_OBSERVING_SETUP DARK DARK o2dcr 31 5 DARK o2dcr 6 1 5 DARK o2dcr 15 1 5 DARK o2dcr 60 1 5 DARK o2dcr 120 1 5 DARK 02dcr 600 1 3 LUCIFER User Manual Issue 1 1 69 FLUSH_DETECTOR DARK mer 600 1 2 FLUSH_DETECTOR END_OBSERVING_SETUP START_READOUT_SETUP DIT 2 NDIT 30 NEXPO 3 ROE_MODE 02dcr SAVE_MODE integrated SAVE_PATH data luci YYYYMMDD FILENAME luci_YYYYMMDD_Dark_ END_READOUT_SETUP START_OBSERVING_SETUP DARK DARK DARK DARK DARK DARK DARK FLUSH_DETECTOR DARK END_OBSERVING_SETUP o2dcr 3 o2dcr 4 1 o2dcr 5 o2dcr 10 o2dcr 20 o2dcr 30 BW WwW w w a mer 300 2 3
30. DELTI 0 00003333 CDELT2 0 00003333 CTYPEL RA TAN CTYPE2 DEC TAN CROTAL 315 000000 CROTA2 315 000000 CD1 1 0 00002357 CD12 0 00002357 CD2_1 0 00002357 CD22 0 00002357 Telescope information OBJRA 21 52 25 3835 RA requested OBJDEC 02 23 19 556 DEC requested TELALT 56 203419 LBT mount altitude at MJD OBS TELAZ 150 097107 LBT mount azimuth at MJD OBS PARANGLE 24 5389 Parallactic angle at start deg POSANGLE 45 0000 position angle at start deg ROTANGLE 437 4367 rotator angle at start deg M1 X 0 272624 X pos of PM M1 Y 1 975723 Y pos of PM M1 Z 1 568008 Z pos of PM MIRX 51 267850 X rot of PM M1RY 13 041830 Y rot of PM M1RZ 0 000000 Z roy of PM M1CTEMP 8 549333 temp of PM M2 X 7 010000 X pos od SM M2 Y 3 879000 Y pos of SM M2 Z 0 000000 Z pos of SM M2RX 148 650000 X rot of SM M2RY 181 800000 Y rot of SM M2RZ 0 000000 Z rot of SM 58 Issue 1 1 LUCIFER User Manual M2CTEMP 8 549333 temp of SM M3TIP 0 000000 tip of TM M3TILT 0 000000 tilt of TM M3PSTN 0 000000 position of TM M3ZROT 0 000000 Z rot of TM M3CTEMP 8 533334 temp of TM TTEMP201 8 291000 telescope temp at sensor 201 TTEMP202 8 711000 telescope temp at sensor 202 TTEMP203 8 845000 telescope temp at sensor 203 TTEMP204 8 514000 telescope temp at sensor 204 TTEMP205 8 765000
31. Document Name Document Number Issue Number Issue Date Prepared by LUCIFER User Manual LUCIFER_UM_1 1 pdf LBT LUCIFER MAN 015 1 1 December 24 2009 LUCIFER commissioning team Issue 1 1 LUCIFER User Manual Distribution List Recipient Institute Company No of Copies Document Change Record Issue Date Sect Paragr affected Reasons Remarks 0 1 11 26 07 all new document 0 2 01 11 08 all minor changes 0 3 03 28 08 3 1 9 Appendix B added changed filter curves 0 31 01 29 09 Appendix B added filter curves 1 0 11 20 09 Al Update before release 1 1 12 24 09 Tab 8 Corrected full well Tab 12 Corrected Ks ZP 6 6 2 7 2 2 7 3 Updated with more information Note Chapter 5 fully related to LBT issues has been written by Dave Thompson from LBTO LUCIFER User Manual Issue 1 1 3 Contents List of Figures List of Tables Introduction N 3 LUCIFER 3 1 Instrument description 3 1 1 Entrance window 3 1 2 Focal Plane amp Slit Masks 3 1 3 Collimatorl 3 1 4 Gratings 3 1 5 Pupil Viewer 3 1 6 _Cameras 3 1 7 Filters 3 2 Detector and Acquisition System 3 3 Calibration Unit 4 Observing in the NIR 4 1 Atmospheric Transmittance 4 3 Imaging 4 4 Spectroscopy 5 O
32. FER User Manual Issue 1 1 61 C Additional filter information Table 19 Specifications for the filters Operating Temperature Blocking Thickness Quality AOI AR Coating Wedge 60 K i e 213 C ODA from 0 8 to 3 0 1 7 0 0 6mm A 2 per inch image quality suppression of internal ghosts normal incidence 0 in parallel beam on outer surface s if applicable lt 30 arcsec Clear Aperture Size Peak Transmission Tolerance CWL Tolerance FWHM 66 x 80 mm 62x 62 mm 71x85mm 67x67 mm 0 0 mm 0 2 mm gt 80 gt 65 E 10 10 of FWHM 5 10 of FWHM Table 20 Characteristics of the current LUCIFER 2 filters Name LUCIFER Ac um FWHM um peak Taverage z ED034 2 2 0 965 0 196 93 8 89 9 J ED044 2 1 250 0 301 90 9 87 1 H ED024 2 1 651 0 291 92 1 85 4 K ED059 2 2 199 0 408 92 1 845 K ED046 1 2 2 161 0 270 91 7 85 9 Order Separation ED763 2 2 1 953 0 998 95 7 88 3 Brackett y ED477 2 2 2 171 0 023 83 1 82 0 Fell ED468 2 2 1 645 0 018 911 88 0 H2 ED469 2 2 2 127 0 023 83 9 82 0 Paschen 3 ED476 3 2 1 284 0 013 85 8 85 2 Paschen y ED467 4 2 1 096 0 010 70 4 68 9 C 1 Filter Curves C 1 1 Broad Band Transmission Transmission Transmission 62 Issue 1 1 LUCIFER User Manual z filter 0 8 0 85 0 9 0 95 1 1 05 HAN Wavelength pm H filter 1 4 1 5 1 6 1 7 1 8 1 9 Wavelength pm Ks filter
33. File pull down menu top left of the panel and subtract it from the acquisition image Then use the Telescope LUCIFER User Manual Issue 1 1 53 Control GUI SHIFT IMAGE amp ROTATE IMAGE buttons If a rotation is needed apply it first and then shift the object as needed The SHIFT IMAGE button opens a new panel which leads the user through the procedure 1 Click in the Skycat GUI to define the reference position and 2 click in the Skycat GUI to define the new position In detail First of all the image on which you want to do the measurements has to be opened in Skycat Then click yes in the option panel Now choose the reference object star in Skycat click on it pick object and wait for a second or two Skycat performs a 2D Gauss fitting on the object Once finished click on the position where the reference point should be moved to center of slit Again Skycat will make a fit and the calculated offset needed will appear on the Telescope Control GUI under the Offset Telescope area in the X Y textfield Pressing the small COMMIT button located below will trigger the telescope offsetting The ROTATE IMAGE button opens a similar pop up window as in the case of SHIFT IMAGE The steps to follow are actually the same except that a rotation offset will then be provided instead of a displacement offset Careful If a non zero rotation offset angle exists in the PA entry of the Offset Telescope area of the Telescope Con
34. ITTER OFFSET OFFSET POINTING FLAT FLAT FLAT LAMP DARK FLUSH_DETECTOR END_OBSERVING_SETUP Notes on script 05 02 50 20 40 50 05 03 00 20 40 30 50 position active mer INTEGRATED data luci 20080911 script_ absolute DETXY 20 20 10 40 0 10 00 10 00 45 6 06 40 40 21 23 30 06 40 59 2 mer 10 0 5 10 mer 10 0 1 10 Ks clear N1 8 Xe 10 o2dcr 60 0 5 10 HO HH HH HO OH OH OH HOH 1 HO OH OH HH hh mm ss dd mm ss any name or leave blank hh mm ss dd mm ss in degrees position parallacticlidle activelguide track any positive value no blanks allowed any positive value no blanks allowed as NDIT o2dcr o2scr msr mer ttreads lir integrated cube normal absolute save path root of the filenames relativelabsolute DETXY RADEC wait after offset jitter pattern with 10 exposures a maximum offset distance of 40 0 arcsecs offset from TARGET_COORD same as above with a rot angle offset of 45 6 24 00 new pointing coords readout with DIT 3 0 NDIT 5 NEXPO 10 specify additional instrument setup readout using last readout setup turns on the Xe lamp for 10 secs indicate DARK instead of FLAT executes a flush readout of the detector no parameters no images are saved e There was a typo in the script parsing so the end of the observing set up had to be written END_OSERVING SETUP the only correct text to be used for the scripts
35. MMIT button sends the new setup to the telescope service Pointing On the left side of the GUI the current position of the telescope is shown including the rotator position and parallactic angle It is updated regularly so the user is able to follow the telescope motion Note When these text fields are empty it indicates that a connection to the TCS is not working properly or a subsystem is not running on the TCS side This can be checked by the Telescope Operator Offset Telescope This panel is necessary for the acquisition process The user can choose a position angle PA offset and telescope position offsets There are three pull down menues available e CoordSys Lets the user choose the valid coordinate system 1 RADEC Offsets are interpreted as sky coordinate offsets 2 DETXY Offsets are interpreted as detector coordinate offsets This option is useful for the acquisition procedures LUCIFER User Manual Issue 1 1 45 Telescope Control TELESCOPE CONTROL fa 12 45 03 ve LST 11 22 26 Authorized LUCIFER BF ri Pointing Current Target Current Guide Star Current Telescope Setup 37 35 7 RA 12 37 35 Name goodsn107 Name guide star PA 7 0 DEC 62 15 48 7 RA 12 37 35 650 RA 12 37 43 0240 ROT MODE POSITION AZ 16 55 Alt 58 14 DEC 6215 42 030 DEC 62 19 1 06 TEL MODE ACTIVE ROT 163 74 PA 0 0 Guiding ready Side left Ha His Bad Star Counter 0 PAR 149 13 OffsetTelescope Next Target Next Guide Star Next Tele
36. S image must be distortion corrected with high accuracy and the plate scale has to be known with high accuracy catalog positions must have high astrometric accuracy 2 Science sources and reference stars have to be taken from the same image or catalog Their relative positions have to be known to better than 1 6 of the slit width otherwise slit losses occur 3 At least two reference stars have to be defined within the LUCIFER field to compensate for pointing and image rotation offsets Five reference stars are recommended for higher accuracy The maximum number of reference stars has been set to ten 4 It is strongly recommended to limit yourself to a maximum of 40 slits per mask Slits are generated with the default settings for type length and width Changing the default settings will affect newly created slits as well as already existing ones Slits can be modified and deleted individually by clicking on their number and width labels When all slits have been positioned the setup can be saved During this process four files are generated 1 a Ims file containing the instrument parameters all slit reference star and guide star positions as well as all slit parameters This file can be loaded again to restore the session 28 Issue 1 1 LUCIFER User Manual 2 a epsf file containing a picture of the mask for direct view does not show the mask ID 3 two Gerber files grb and _v2 grb cointaining the information for mask c
37. S x mM N AYSUaIU anjo ay Figure 16 Normalised spectrum of the K band night sky 210_zJHK grating N1 8 camera where the OH lines are identified LUCIFER User Manual Issue 1 1 37 Table 16 Spectroscopic flat field count rate per second for different slit width 210_zJHK grating Rec Lamp halol halo2 halol halo2 halol halol halo2 Slit Zz J H K N1 8 N3 75 N1 8 N3 75 N1 8 N3 75 N1 8 N3 75 S150 0 25 105 25 250 60 400 100 350 90 S300 0 50 350 90 850 200 1300 350 1100 300 S450 0 75 500 125 1300 350 1900 500 1700 450 S600 1 00 700 180 1700 450 2600 650 2200 550 3 Slit 700 180 1700 450 3100 800 2200 550 only halo2 halo2 halo2 halo2 200_H K grating Recommended Lamp halo2 Slit OrderSep N1 8 camera N3 75 camera S150 400 100 S300 1300 350 5450 2000 500 5600 2600 700 SpecPhot 2600 700 150_Ks grating Recommended Lamp halo2 Slit Ks N1 8 N3 75 S150 200 50 300 550 140 5450 800 200 5600 1100 280 SpecPhot 1100 280 Topic Frequency Comment Flat fields upon observer s request to be taken on sky Photometric standards upon observer s request clear conditions Telluric standards for each spectro observation within 2 hours of the observation and a maximum airmass difference of 0 2 Spectrophotometric standards upon observer s request same as above Spectroscopic arcs amp flat fields for each spectro observation to be taken the morning after the obser vations
38. TART_OBSERVING_SETUP OFFSET_TYPE relative COORD_SYS RADEC ACQUISITION 00 OFFSET 26 61 98 34 END_OBSERVING_SETUP Spectroscopic science template with nodding along the slit START_INSTRUMENT_SETUP CAMERA N1 8 FILTER OrderSep GRATING_UNIT 200_H K CENTRAL_WAVELENGTH 2 106 MASK NB4 MASK_POSITION mask_in_fpu FLEXURE_COMP on END_INSTRUMENT_SETUP START_READOUT_SETUP DIT 100 NDIT 3 NEXPO 1 ROE_MODE mer SAVE_MODE INTEGRATED END_READOUT_SETUP START_OBSERVING_SETUP OFFSET_TYPE relative COORD_SYS DETXY OFFSET 00 00 OFFSET 00 30 OFFSET 00 60 END_OBSERVING_SETUP Spectroscopic lamp calibration using the calibration unit START_INSTRUMENT_SETUP CAMERA N1 8 FILTER K GRATING_UNIT 210_zJHK CENTRAL_WAVELENGTH 2 106 MASK NB4 MASK_POSITION mask_in_fpu FLEXURE_COMP off END_INSTRUMENT_SETUP START_READOUT_SETUP DIT 5 NDIT 1 NEXPO 1 ROE_MODE 02dcr SAVE_MODE normal FILENAME luci_YYYYMMDD_Calib_ 68 Issue 1 1 LUCIFER User Manual END_READOUT_SETUP START_OBSERVING_SETUP LAMP Ar 10 LAMP Xe 10 LAMP HALO2 10 END_OBSERVING_SETUP Example of sky flat script START_INSTRUMENT_SETUP CAMERA N3 75 FILTER Hel GRATING_UNIT mirror CENTRAL_WAVELENGTH MASK MASK_POSITION no_mask_in_use FLEXURE_COMP off END_INSTRUMENT_SETUP START_READOUT_SETUP DIT 4 NDIT 1 NEXPO 5 ROE_MODE 02dcr SAVE_MO
39. _MODE NORMAL END_READOUT_SETUP START_OBSERVING_SETUP 54 Issue 1 1 LUCIFER User Manual OFFSET_TYPE relative COORD_SYS RADEC ACQUISITION 00 OFFSET 26 61 98 34 The offset to get centered on your faint source END_OBSERVING_SETUP Multi object Spectroscopy The exact alignment procedure of the science field using a custom made MOS mask will be detailed in a later version of this user s manual LUCIFER User Manual Issue 1 1 55 References TRANSA http unagi gps caltech edu notes bfats2002 Rousselot et al 1999 A amp A 354 p 1134 56 Issue 1 1 LUCIFER User Manual A Example of fits header General fits header information SIMPLE T BITPIX 32 NAXIS 2 NAXIS1 2048 NAXIS2 2048 COMMENT BSCALE 1 0 BZERO 0 0 COMMENT COMMENT COMMENT COMMENT Time information MJD OBS 55137 05830264 Modified julian date days of observation end DATE OBS 2009 11 02T01 23 57 3480 UT date of observation end DATE 2009 11 02T01 23 58 1050 UT date of file creation UT 5037 3480 01 23 57 3480 UTC sec at EOread LST 75016 640000 local siderial time 20 50 16 EOread ORIGIN Mount Graham MGIO Arizona OBSERVER master TELESCOP LBT FRATIO F 15 INSTRUME Lucifer OPTIC high res Detector related information ELECGAIN 4 100000 electrons DN ENOISE 12 000000 electrons read ELECTRON MPIA IR R
40. aracteristics are summarised in Tab El Readout Modes 16 Issue 1 1 LUCIFER User Manual Table 7 Characteristics of the filters installed in LUCIFER 1 The position indicates in which filter wheel FW the filter is installed Name LUCIFER Position Ac um FWHM um Tpeak Taverage z 3002 1 FW2 0 957 0 195 98 4 94 3 J 0403 1 FW2 1 247 0 305 91 2 83 2 H 4302 1 FW2 1 653 0 301 95 0 90 5 K 3902 1 FW2 2 194 0 408 90 1 85 7 K 3902 1 FW2 2 163 0 270 90 7 86 8 Order Separation ED763 1 1 FW2 1 950 0 981 95 0 86 3 Br_gam Brackett y ED477 1 1 FW1 2 170 0 024 79 4 76 5 Fell ED468 1 1 FW1 1 646 0 018 91 2 89 5 H2 ED469 1 1 FW1 2 124 0 023 87 9 84 9 Hel 1085 15 1 FW1 1 088 0 015 65 2 64 6 J high 1 FW1 1 303 0 108 95 9 93 3 J low 1 FW1 1 199 0 112 95 4 93 3 OH_1060 1 FW1 1 065 0 009 68 6 66 8 OH_1190 1 FW1 1 193 0 010 80 4 78 0 P_beta Paschen ED476 1 1 FW1 1 283 0 012 861 85 5 P_gam Paschen y ED467 2 1 FW1 1 097 0 010 81 1 80 0 Y1 1 FW1 1 007 0 069 67 3 64 2 Y2 1 FW1 1 074 0 065 94 2 89 5 The channel layout is shown in Fig 4 Channels are numbered along the fast direction starting with quadrant I The read modes offered are e DCR double correlated read mode This mode is the default in high background applications where background limited perfor mances are reached easily The detector is first reset then read out Reading of the
41. aterial should be used to avoid problems with stability and warping of the masks during cooldown The masks do not exactly follow the focal surface because they are cylindrical The cylinder radius is that of the focal surface 1033 mm and the shape is defined by the mask frames the cylinder axis is in dispersion direction therefore the defocus is constant along a standard not inclined slit The defocus can be limited to 0 5 mm for the central area of 4 armin height and 2 5 arcmin width in dispersion direction The limitation to this central area is sensible because spectral clipping by the detector array increases with increasing distance of the slit from the field center The exchange of masks is a daytime operation that needs about one week to be prepared e mask cutting at LBTO in Tucson e the newly cut masks sheets have to be installed in frames that have to be put in the cabinet that will then be inserted in LUCIFER e the auxiliary cryostats one empty to receive the cabinet currently in LUCIFER and the other one containing the newly filled cabinet of masks to be inserted have to be cooled down On the day of the exchange the empty cryostat is attached to LUCIFER A bridge vacuum seal is pumped the exchange gate is then opened and the currently used cabinet of masks is moved out of LUCIFER Thereafter the gate is closed the vacuum bridge put back to atmospheric pressure so the auxiliary cryostat can be detached from LUCIFER
42. ations either imaging with narrow band filters or spectroscopic long integrations A number of reads is performed after the reset and the same number of reads is performed after the integration time The signal is the average of the difference of always 2 endpoint samples Fowler pair all pairs have the same double correlated integration time The number of samples for the offered mode has been fixed to 10 endpoints which is equal to 5 Fowler pairs compromise between reduced noise and increased minimum integration time mer mode of Lucifer is based on the o2dcr mode with the same additional clocking after the frame reset to prevent problems with the first frame Figure 5 illustrates how the currently offered LUCIFER readout modes work Reset Reset Reset Reset yal N final reads O Voltage Voltage 2 read O AS o AS we SS F D O 1 read O O N initial reads a time time Figure 5 Illustration of the way the LUCIFER readout modes work DCR to the left MER to the right 18 Issue 1 1 LUCIFER User Manual Figure 6 shows a typical LUCIFER dark frame where some known artefacts are highlighted The two main nasty features are a bad column at x 783 784 for y 1025 2048 and a bad line at y 859 861 over the x range of 670 1025 As much as possible avoid putting any of your spectrum over the area The central line column 1024 1024 of dots are some features of the DCR readmode They
43. bserving at the LBT 5 1 Introduction 5 2 Pointing amp Collimation 5 3 Guiding 10 10 10 11 11 12 13 13 14 15 15 18 19 19 19 19 19 20 20 4 Issue 1 1 LUCIFER User Manual 26 6 1 Available tools eo RE ER ER ee A ed ee ee 26 6 1 1 Exposure Time Calculator ETC 26 6 1 2 LUCIFER Mask Simulator LMS 26 oe ee ee eee een AA ot 28 6 3 Overhead Calculations 28 ee EA E 29 6 0 Oky emissivity 5 a asa A A RA du 29 AE PEE EEE 30 6 5 2 Spectroscopy G w e EEE DEEE de da A e da A 31 So ORR he ee ea ee E A RA de 32 fa a DR BA ee ee Sk a ah es ee ree Oe Bee eS 32 ibd ph eee ee Peewee Sade ea hadddd tit agus 34 PO Gh Reo SEMEN A AS Bee ee 35 41 7 1 Login and Software Start 41 7 2 Interactive Observing 41 7 2 1 The Instrument Control GUI 41 7 2 2 The Telescope Control GUI 44 7 2 3 The Detector Read Out GUI 47 T3 Script Observing i ea 2 4 4 4 4 4 NUE e 48 ies an PEE a de SN NS MR dad ane Ose oe A 52 AE se aa ea ba A8 wa OO SG SE ROS 2 ee ae we 52 are 52 55 56 60 61 ae DAT A AE RES Si een eme 61 CLL Broad Band 4 4 4 6 aa ia ob db Sead dd de Ada ae OES 61 C L2 Narr
44. btained on spectrophotometric standard stars for all spectroscopic modes Two stars were used FS6 z 13 06 J 13 271 H 13 321 K 13 404 UKIRT magnitudes FS29 z 12 98 J 13 215 H 13 255 K 13 33 UKIRT magnitudes In z band one is readout noise dominated in J band depending on the water vapor in the atmosphere one goes from readout noise dominated to sky background dominated For H amp K spectra are sky background dominated irrespective of the grating used Recommended DITs and NDITs To avoid unnecessarily long calibrations in the morning it is recommended to use one of the following DIT NDIT combination for spectroscopic integrations e for bright 4 5 lt Vmag lt 6 tellurics 2sec 15 e for fainter standards 6 lt Vmag lt 10 30sec 2 or 60sec 1 32 Issue 1 1 LUCIFER User Manual Transmission 0 80 1 20 1 60 2 00 2 40 Wavelength um Atmosphere H J high z K J J high Figure 13 Plot of the LUCIFER broad band filters overlaid on a typical atmospheric spectrum Table 14 Typical sky count rate measured between OH lines for the 210_zJHK grating with the 10 slit Filter Count rate Comments ADU sec pix Z lt 0 1 Readout noise dominated J lt 0 2 J 0 5 for 1 slit Illustrates the variability H 0 8 Sky background dominated K 3 blue part of spectrum Sky background dominated 16 red part of spectrum dominated by thermal back ground depending on the wav
45. cabinet Remarks Optic Sieve 990063 0 array of pinholes for imaging amp N3 75 camera Spectro Sieve 990001 1 pinhole array for spectroscopic calibrations Closed Blind 990031 3 used for darks measurements LS 600 990034 4 1 00 slit LS 450 990029 5 0 75 slit LS 300 990032 6 0 50 slit seeing limited N1 8 LS 150 990065 7 0 25 slit seeing limited N3 75 3_slit 995623 8 3 centered vertical slits of 10 x30 for spectrophotometric standards 3 1 4 Gratings The grating unit holds one mirror for the imaging mode and 3 gratings The laboratory measured efficiencies of the gratings are presented in Appendix Additionally the main characteristics are summarized in Tab The difference in peak efficiency between the diagrams in Appendix B manufacturer data and the values given in Table 4 is due to the fact that the gratings are used in non Littrow configuration in LUCIFER Table 4 Characteristics of the gratings The resolution is given for the N1 80 with 2pixel sampling at the peak wavelength 1 The 200 H K and 150_Ks grating do not have a cut off within our wavelength range Order Apeax mm Max Efficiency 50 Cut on um 50 Cut off um Resolution High resolution grating with 210 lines mm 2 2 44 68 2 02 3 18 6687 3 1 64 77 1 41 1 90 7838 4 1 24 76 1 09 1 41 8460 5 1 00 72 0 89 1 11 6877 H K grating with 200 lines mm 1 1 87 83 1 38 gt 2 400 1881 H 2573 K Ks grating wi
46. ccess as user Table 18 Definition of the lamps in the calibration unit Name of the lamps in the Telescope Control GUI Position 1 2 3 4 5 6 Name of the lamps in the Calibration Unit GUI Name Ne Ar Xe halol halo2 halo3 Comment Arc lamps for wavelength calibration Halogen lamps for flat fields The lamp intensity decreases from 1 to 3 Calibration Unit Lamp Control Switch on lamp for ON Ne OFF Ne pan 0 Z seconds 0 endless ON Ar OFF Ar sore 0 Z seconds 0 endless ON Xe OFF Xe OFF 0 E seconds 0 endless ON HALO1 OFF HALO1 OFF 0 5 seconds 0 endless ON HALO2 OFF HALO2 OFF 0 e seconds 0 endless ON HALO3 OFF HALO3 OFF 0 3 seconds 0 endless Deactivate all lamps Edit Configuration Figure 20 The LUCIFER Calibration Unit GUI Flexure Compensation panel In the flexure compensation panel the current flexure mode of the instrument is shown and can be changed via the ON OFF drop down menu When flexure compensation is turned ON using the GUI it is not switched off by running scripts even if they have the flexure compensation flag set to OFF Conversely when the flexure compensation is turned OFF using the GUI scripts can actively switch the flexure compensation on or off depending on the status of the flag Note that at the end of script the flexure compensation is then switched off
47. d together 2 The R theta stage pivot point is 612 mm above the center of the LUCIFER field Limits at 18 degrees restricts the motion to just inside the usable focal plane at the left front bent Gregorian focus So you need to be careful when using guide stars at high field angles and position angles that put them near these limits 3 The focal plane delivered by the telescope is blocked by parts of the AGw at field angles of more than 330 arcsec radius 4 The tertiary mirror is a bit undersized and there is some vignetting visible in the wavefront sensor at high field angles gt 3 5 arcmin While the wavefront sensor algorithms have been adjusted to account for this selecting guide stars inside a radius of 240 arcsec from the science target would be better than those outside 5 The probe emits thermal radiation and appears bright in the K band and at all wavelengths it shadows the LUCIFER entrance aperture when close to on axis The apparent size of the probe is 2 arcmin across or about half the LUCIFER field of view If this will cause problems for your project you need to be careful in the selection of your guide star and the orientation of the field for your observations Odd shadows or emission on LUCIFER are likely from the guide probe Under fully closed loop operations ACTIVE mode where the same guide star is used at two offset positions in the patrol field the positioning accuracy of the source in the LUCIFER field of view
48. detector is always non destructive After the selected integration time the chip is read out again The difference of the two read out frames removes detector channel and pixel specific properties which are present in both frames and preserves the integration charge value The o02 of the o2dcr mode stands for some additional line clocking after the frame reset which were necessary for most HAWAII 2 detectors tested for Omega2000 to get rid of strange ramps Table 8 Characteristics of the detector Pixelsize Number of pixels Fullwell Linearity Quantum efficiency Readout mode Min Exposure time Gain RON DC 18 0 um 2048 x 2048 pixel 260000 e7 better than 5 at 80 full well z 0 25 J 0 33 H 0 74 K 0 73 Double Correlated Reads Multiple Endpoint Reads DCR MER fixed at 10 samples 2sec 10 sec 4 083 e ADU 3 93 e ADU lt De lt 5e7 0 06 e s pix 0 06 e s pix to be confirmed LUCIFER User Manual Issue 1 1 17 A aor tt B A A fi d p i ST Ee eee SSS eS ee Figure 4 Detector Layout The arrows indicate how the four quadrants are read and which is the direction of the slow amp fast reads in the first frame to enable correct data reduction e MER multiple endpoint read mode This mode also called Fowler sampling reduces the read noise by the square root of the number of reads It is particular well suited for faint objects observ
49. ds covered by the LUCIFER optics include z J H and K i e the range from 0 85 to 2 5 um In practice however the observing range is limited on the blue side by the cut off wavelength of the entrance window 0 87um section 3 1 1 and on the red side by the cut off of the atmospheric window after 2 4um The main observing modes are summarized in Tab I and Tab Table 1 LUCIFER s imaging modes Camera N1 8 N3 75 N30 non available yet Scale pixel 0 25 0 12 0 015 FOV arcminute 4x4 4x4 0 5x 0 5 Comments FOV limited by isoplanatism Table 2 LUCIFER s spectroscopic modes LSS stands for Long Slit Spectroscopy and MOS for Multi Object Spectroscopy Camera N1 8 N3 75 N30 non available yet Scale pixel 0 25 0 12 0 015 FOV arcminute 4 x 2 8 4 x 2 8 0 5 x 0 5 Resolution 2pix 1900 8500 3800 17000 10000 40000 Comments LSS amp MOS LSS amp MOS LSS full coverage zJHK 3 1 1 Entrance window The instrument entrance window is tilted by 15 in order to reflect the visible light to the on axis wavefront sensor for adaptive optics The current entrance window has a blue cut off wavelength at 0 87 pm as illustrated in Fig Transmission Entrance Window 1 Transmission Entrance Window 1 100 0 99 0 98 0 397 0 O 96 0 S 2 95 0 2 E 94 0 a 93 0 E 92 0 91 0 90 0 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600
50. e o2dcr v NDIT 1 Savemode integrated NDIT 1 Savemode integrated v exposures 1 NEXPO exposures 1 NEXPO Filename root luci_20091117_ Filename root luci_20091117_ Save Path home observer data 20C Save Path home observer data 20C Figure 22 The LUCIFER Read Out Manager GUI All necessary detector parameters can be set from this GUI 7 2 3 The Detector Read Out GUI The third control GUI for interactive observations with LUCIFER is the Readout Control GUI Fig 22 The left region of the GUI shows the current detector set up values like e g the read out mode in use the integration time the last and next file names of the images etc The countdown clock located in the upper left corner indicates whether an integration is currently on going A static time value on a black background as shown in the figure indicates that the detector is currently idle When a readout is started the clock changes to a yellow background and the remaining integration time for one exposure starts to count down The right part of the GUI allows to set new readout DIT NDIT NEXPO values and to start stop exposures The Start Read button starts an integration with the current settings displayed in the left part The Abort button can be used to stop the on going integration Note no confirmation window will be displayed before the integration is stopped To determine that images should be saved manually or automatically t
51. eadout setup area If this button is orange changes in the readout setup have not yet been sent since the last time the button was pressed Like the Save image button this button changes to green when the changes have been sent successfully At this point the information on the right and left side of the panel should be identical To be able to sent a new readout setup all values have to be set to sensible i e non negative values The Filename root and Save Path fields can be left blank however In this case the current values will be left unchanged After a read the newly observed image is displayed on the LUCIFER display Fig 23 This display does not offer as many options as a typical SkyCat but allows to have a quick check at the data taken sky object counts amp centering On the top right part of the panel few statistics vaues calculated over the small window represented above it are provided For a quick look image analysis as well as for the acquisition procedure the image has to be saved This triggers an automatic uploading of the frame in the SkyCat display on same desktop 7 3 Script Observing Usually observations with LUCIFER will be performed by means of ASCII scripts These scripts allow the setting of all relevant instrument parameters as well as the control of the telescope Scripts are very convenient and help significantely to maximize observing efficiency The scripts are structured to clea
52. electronics Vers 2 STRT INT 4934 6013 01 22 14 6013 start integration sec UT STOP INT 5037 3432 01 23 57 3432 stop integration sec UT OBJECT FS29 EXPO_NO 2192 exposure read counter FILENAME luci_20091101_0001 fits TPLNAME macro template name TIMERO 1984 milliseconds TIMER1 3000 milliseconds TIMER2 1016029 microseconds PTIME 2 pixel time base index READMODE 02 double corr read read cycle type IDLEMODE break idle to read transition SAVEMODE o2 double corr read save cycle type CPARi 1 cycle type parameter ITIME 3 000000 on chip integration time secs CTIME 5 105992 read mode cycle time secs LUCIFER User Manual Issue 1 1 CRATE 0 195848 read mode cycle rate Hz HCOADDS 1 of hardware coadds PCOADDS 1 of coadded plateaus periods SCOADDS 20 of software coadds NCOADDS 20 effective coadds total EXPTIME 60 000000 total integ time secs FRAMENUM 1 INTEGRAL OF 20 SKYFRAME unknown SAVEAREA 1 2048 1 2048 SOFTWARE GEIRS Vers hwplx r251 sv9b x04 Sep 17 2008 22 35 45 COMMENT your comment WCS information CRVAL1 328 08217135 CRVAL2 2 38875000 RA 21 52 19 721123281 RA at MJD OBS DEC 02 23 19 542202486 DEC at MJD OBS RADECSYS gt FK5 CRPIX1 1014 060000 CRPIX2 1043 510000 SECPIX1 0 120000 SECPIX2 0 120000 C
53. elength spectral type and seeing conditions e for science observations 120sec 1 300sec 1 600sec 1 For all integrations longer than 60 seconds it is always imaging or spectroscopy recommended to use the MER mode which has a lower readout noise and better cosmetic The main limitation for the integration time is given for sky background dominated modes by the sky itself and specifically the OH line intensities In K band with the 1 slit peak counts of up to 12000 have been measured on OH lines An example is given in Fig which also illustrates the fact that these lines varies with time but essentially independently of the airmass 6 6 Calibrations 6 6 1 Sky flats Sky flats are taken around sunset sunrise with the telescope pointing at zenith the ventilation doors closed and the observing doors facing away from the sun The instrument is at nominal rotator angle LUCIFER User Manual Issue 1 1 33 K band signal object counts pixel sec K band signal sky counts pixel sec 2 0 T T T T 1 30 T T T T 25 155 A 20 noH fa a LS 15 ah Re APN y 0 5 Ya ht WA ate i eee 5 WY Mu AL AS AA l 4 0 0L Oe 1 1 1 20x 10 21x10 2 2108 23x10 2 4x10 2 0x10 2 1x10 2 2x10 2 3x10 2 4x10 Wavelength Angstroem Wavelength Angstroem H band signal object counts pixel sec H band signal
54. encies of the efficiency for the 210_zJHK grating 60 25 Wavelength dependencies of the efficiency for the 200_H K grating 60 26 Filter curves for broad band filters Red filters installed in LUCIFERI 62 LUCIFER User Manual Issue 1 1 7 27 Narrow band filter curves Part D o oo e 63 28 Narrow band filter curves Part 2 If not otherwise specified the red curves are the filters present in LUCIFER1 When specified e g for Y1 Y2 then both filters are present in LUCIFER1 8 Issue 1 1 LUCIFER User Manual List of Tables Multi Object Spectroscopy a 3 Permanently installed masks 13 4 A serbe ae du due gagne tt UE Le un ee Se ek ae de wy 13 5 Wavelength coverage for the gratings with the N1 80 camera at the nominal center wavelength For the N3 75 camera multiply AA by 0 48 14 6 Wavelengths which can set at the center of the detector Careful the ranges given represent the physical limits of what can be achieved with the grating tilt and does not take into account the limits of the filters used for order separation 14 Characteristics of the filters installed in LUCIFER 1 The position indicates in which filter wheel FW the filter is installed 16 8 Characteristics of the detector 16 12 LUCIFER s i
55. ging long integration of faint objects at short wavelengths e g in z band the increased sky illumination may need to be taken into account The Moon illumination is however a problem for the guiding system which works at optical wave length It is therefore recommanded to avoid observing closer than 30 degrees from the Moon to avoid possible contamination effects on the wavefront sensor of the guider system 5 Observing at the LBT 5 1 Introduction The Large Binocular Telescope uses an azimuth elevation mounting Two 8 4 meter diameter primary mirrors are mounted with a 14 4 meter center to center separation Some basic characteristics are summarized in Table 9 The LBT is unlike every other major telescope in that the design is highly asymmetric The primary mirrors are cantilevered off a central pair of elevation C ring bearings These elevation C rings have extensions that support one armed A framed swing arms that allow the secondary and tertiary mirrors as well as the prime focus cameras to swing into or out of primary mirror optical axis The primary M1 and secondary M2 mirrors are mounted on hexapods that allows them a considerable range of LUCIFER User Manual Issue 1 1 21 motion 3 mm for M1 10 mm for M2 in six axes The tertiary M3 has a smaller range 1 mm and only four degrees of freedom It is this adjustability that will allow the LBT to operate efficiently as a fully binocular telescope Table
56. he pull down menu next to the Save image button is used The color of this button also indicates whether the last image has already been saved the button is green or not the button is orange Note Changing the selected save mode value from manual to automatic would save data if that action takes place before an integration or a read but does not save the last frame already read automatically Note When saving an image for the first time after changing some of the detector readout setting values e g the ROEmode or the DIT or the filename frequently a pop up containing following message appear There might have been a problem while saving If the image has appeared on the automatically updated SkyCat then you know it has been saved properly Most of the time the image is nevertheless saved correctly but please check on disk In case of such a message the Save image button remains orange instead of turning green The Frame type pull down menu determines the value of the OBJECT and DATATYPE keywords that will be written into the FITS header of the image When the datatype is SCIENCE the OBJECT keyword value for the fitsheader will be read from the telescope service at the beginning of the integration For any other selection the OBJECT keyword in the fitsheader will be set to 48 Issue 1 1 LUCIFER User Manual undefined The lower right area of the GUI allows to set the values for a new
57. ience dedicated templates for NIR observations are made available and exam ple scripts presented in Appendix D can be found in TemplateScripts Examples on the LUCIFER workstation The scripts are started by using the shell script executeLUCIScript sh available at the prompt on any observer terminal The list below shows all possible parameters that can be used for a script Comments to all possible entries are provided on the right handside All parameters presented in the _OBSERVING_SETUP can of course not be used all in one single script especially since some are meant for science observations and others for calibration purposes START_INSTRUMENT_SETUP CAMERA N3 75 N1 8 N3 751N30 FILTER Ks Br_gam name of one or two filters GRATING_UNIT mirror mirror 210_zJHK 200_H K 150_Ks CENTRAL_WAVELENGTH value or leave blank MASK IDxxx mask id NBxx cabinet position leave blank for no mask MASK_POSITION no_mask_in_use mask_in_fpu mask_in_turnout no_mask_in_use FLEXURE_COMP 50 Issue 1 1 LUCIFER User Manual on enable flexure compensation END_INSTRUMENT_SETUP START_TELESCOPE_SETUP test star any name or leave blank TARGET_NAME TARGET_COORD GUIDE_NAME GUIDE_COORD ROT_ANG ROT_MODE TELESCOPE_MODE END_TELESCOPE_SETUP START_READOUT_SETUP DIT NDIT NEXPO ROE_MODE SAVE_MODE SAVE_PATH FILENAME END_READOUT_SETUP START_OBSERVING_SETUP OFFSET_TYPE COORD_SYS ACQUISITION J
58. imation corrections are applied by physically moving the optics of the telescope In some conditions M1 can hit one of its software travel limits Tf this occurs you must stop observing and ask the telescope operator to recover from this Please keep in mind that with its very fast primary mirror f 1 14 the LBT is very sensitive to changes in the positions of the optics so open loop collimation noticeably degrades in a few minutes It is thus far more desireable to operate in closed loop which is defined as ACTIVE mode The standard collimation cycle takes a 30 second exposure on the reference star to average over atmospheric effects The whole cycle integration readout processing application of wfs corrections currently takes 45 seconds Because the wfs integration cannot be interrupted we recommend that observers set up their observations to have a dwell time at each dither position of 75 seconds to ensure that a collimation update is applied frequently With dwell times under 60 seconds you can fall into a mode where the dithers are out of sync with the wfs cycles and you do not get collimation updates The main caveat here is that with faint guide stars and or poor seeing the wfs may have to use longer exposure times to have sufficient signal to collimate In such cases the dwell times will need to be increased correspondingly 5 3 Guiding Because of the way the telescope software interface was built it is currently necessary for obse
59. it for Extragalactic Research is a NIR spectrograph and imager for the Large Binocular Telescope LBT working in the wavelength range from 0 85 um to 2 5 um Currently only one LUCIFER instrument is available at the LBT It is mounted on the bent Gregorian focus of the SX mirror In 2011 an identical instrument will be mounted on the bent Gregorian focus of the DX mirror i e other side of the telescope The observing modes currently available are e seeing limited imaging over a 4 field of view FOV e seeing limited longslit spectroscopy e seeing limited multi object spectroscopy with slit masks As soon as the adaptive secondary will be operational at the LBT following additional observing modes will exist e diffraction limited imaging over a 0 5 FOV e diffraction limited longslit spectroscopy Spectroscopic observations can be carried out with a resolution of up to 17 000 seeing limited and 40 000 TBC diffraction limited The instruments are equipped with Rockwell HAWAII 2 HdCdTe 2048 x 2048 px array 3 LUCIFER 3 1 Instrument description Figure 1 shows the optical layout of LUCIFER Collimator Lenses_2_3 Fold Mirror_4 Fold Mirror_3 Fold Mirrors_2 3 Fold Mirror_1 Fold Mirror_2 Grating Mirror Focal Plane Entrance Window Figure 1 LUCIFER optical layout LUCIFER User Manual Issue 1 1 11 The wavelength ban
60. its of what can be achieved with the grating tilt and does not take into account the limits of the filters used for order separation of the camera the other one is placed in one of the positions of filter wheel 1 Fig 3 presents a current pupil image of LUCIFER Because of the structure of the one armed swingarm support the diffraction spikes are not standard The LBT PSF has an asymmetric 10 armed diffraction pattern rather than the usual 4 arm from typical spiders The displacement of the pupil to its stop causes presently a light loss of about 17 This will be corrected during the next warm up of the instrument 3 1 6 Cameras N1 8 This camera is designed for seeing limited spectroscopy for covering one single broad band z J H or K The image scale of this camera is 0 25 pixel The maximum distortion is less than 0 1 within the 4 arcmin field It can also be used for imaging in seeing limited mode but bear in mind that the lateral color is not corrected N3 75 Itis dedicated for both seeing limited imaging and seeing limited slit spectroscopy The image scale of this camera is 0 12 pixel In spectroscopic mode it covers about half of the zJHK bands wavelength range at higher resolution for an equivalent slit width defined in pixel compared to the N1 80 camera N30 This camera 0 015 pixel is intended to be used for diffraction limited imaging and longslit spectroscopy together with the adaptive optics The sampling
61. l lines not the brightest not the faintest To increase the signal to noise on these lines without saturating you increase NDIT keeping DIT constant With the exception of z Band where Argon and Xenon lamps are recommended to be used at the same time all other calibrations can perfectly be performed using only the Argon lines Do not forget to move manually the calibration unit in and out of the field of view via the Instrument Manager Panel 6 6 3 Calibration Plan The calibration plan on a long term is the responsability of the LUCIFER LBTO instrument scientist We however shortly highlight our recommendations 36 Issue 1 1 LUCIFER User Manual 7 AF J TE LAA AA age pet aye A See ie tee J dati _ gt e A TSGLLOZ Ie 4 FOGLI Sara setn is Siar SS Sts eS ASES D EECOE TI a i J S ZLvOZ AE J CERTE ES ER i RE F O E9SOZ 3 J CELIA SS tare ioe Se Sa e R A a GEOBDG LE TETE ES L SS ES Soy ET ee ee E AR A A O eee op Recetas Lx ZE El le NE un o Jo 9 1iz Lt lt 6 8bZ1Z pa J 5 gt o J 8908 1z ES 18616512 L J COLLI M O 2L8LZ L o FF xX 0 CS0ZZ OT CT e Serr Sea Se aN odds ps J on 7 Pos IN A a mg O En 7 o KO GOBGC ss as A A A A a I
62. maging zero points defined as 1 ADU SEC 31 MVA PA ENT 15 Count rates ADU s for internal flat fields with N3 75 camera 35 16 Spectroscopic flat field count rate per second for different slit width 37 17 Arc lines count rate per second The integration time are for each lamp separately but they of course can be switched together The counts are given for the brightest B lines and the average of the other typical fainter lines T 38 18 Definition of the lamps in the calibration unit 43 19 Specifications for the filters 61 20 Characteristics of the current LUCIFER 2 filters 61 LUCIFER User Manual Issue 1 1 1 Acronyms AO ADC AGw DARK DIT NDIT FIMS FOV FPU LBT LMS LUCIFER RON wis adaptive optics atmospheric dispersion corrector acquisition guiding amp wavefront sensing system dark current detector integration time number of detector integration time FORS Instrument Mask Simulator Field of View Focal Plane Unit Large Binocular Telescope LUCIFER Mask preparation Software LBT NIR Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research readout noise wavefront sensor 10 Issue 1 1 LUCIFER User Manual 2 Introduction LUCIFER LBT NIR Spectrograph Utility with Camera and Integral Field Un
63. n script which is available in the Template Scripts Examples on the lucifer machine 52 Issue 1 1 LUCIFER User Manual 7 4 Target Acquisition Target acquisition is needed mostly uniquely for spectroscopic acquisitions and has to be set in a script separately from the science script Under given special circumstances in imaging mode one may wish to refine the pointing on a given science field but normally no acquisition is needed for this observing mode 7 4 1 Imaging When wishing to perform deep imaging and thus many new presets may be needed it might be good to check the field on the acquisition image before starting a script This is easily done by performing a quick manual read of the detector It sometimes directly shows an obvious shift in position of your field corresponding to the fact that the guide star found by the guider did not correspond to the one you selected In principle if that automatically found other guide star is suitable for guiding and the centering is not important for you you can continue like this Bear in mind however that this is a strong indication that a telescope pointing correction is needed 7 4 2 Spectroscopy The steps involved in a spectroscopic acquisition are e Preset the telescope to the new position e While this is happening move the mask to the FPU e Once guiding is started take a through slit image with short exposure time amp save it e Move the mask to the
64. n imaging mode with the N3 75 camera and all available filters Table 12 presents the derived zero points for all filters Please note that the LUCIFER1 z amp J broad band filters are wider than the corresponding atmopheric windows as illustrated in Fig L3 As a consequence the measured zero points in these bands are quite sensitive to the amount of water vapor in the atmosphere resulting in flux variations of 3 in z and 6 in J when the atmospheric water vapor doubles Table 13 presents some 3 sigma limiting magnitudes derived assuming a seeing of 0 8 an airmass of 1 5 and 3mm of water vapor using a DIT of 10 sec and NDIT 360 to obtain one hour on source integration LUCIFER User Manual Issue 1 1 31 Table 12 LUCIFER s imaging zero points defined as 1 ADU SEC Filter ZP err ZP Br_gam 21 4 0 02 Fell 21 6 0 03 H2 21 45 0 02 Hel 21 9 0 03 P beta 21 47 0 03 P_gam 21 43 0 03 Y1 23 5 0 03 Y2 23 46 0 03 OH 1060 21 5 0 03 OH 1190 21 47 0 03 J_low 24 15 0 03 J_high 23 85 0 03 z 24 5 0 03 J 24 85 0 03 H 24 7 0 02 K 24 45 0 03 Ks 24 02 0 03 Table 13 Imaging limiting magnitude for a SNR 3 in one hour integration Filter Sky mag Limiting mag Zz 17 5 24 4 J 16 0 23 9 H 14 0 22 9 Ks 13 0 22 1 6 5 2 Spectroscopy During clear nights spectrophotometric standard stars have been observed with the 10 wide slit with the N1 8 camera and all the gratings Figure 14 presents typical spectra o
65. nically to a nominal angle as is currently the case for the 150_Ks grating Pupil Viewer Panel This is mostly needed for optical calibrational work and not necessary for the normal observing mode Filter Wheels Here the user can choose the filters to observe with Note All combinations are possible but some might not meaningful so please be alert Commit The COMMIT button is located on the upper right side of the GUI Here the new setup can be executed As long as a component inside LUCIFER is still moving from a former setup the CoOMMIT button is blocked The INITIALIZE button is located left from the COMMIT button After a software restart this button has to be pressed to re initialise all instrument functions During normal operations there is not need to use this button Alarm Status Panel Here the overall status of the environmental systems of LUCIFER is indicated A change in temperature or pressure will be indicated by a warning or an alarm which is color coded red The latter one is very critical and requires an urgent system check by an instrument engineer expert 7 2 2 The Telescope Control GUI This GUI uses a direct service connection to the Telescope Control Server TCS interface An error when starting the Telescope Service might be caused by a non running interface on the TCS side Please inform the LBTO instrument scientist for support The GUI Fig 21 follows the same philosophy as the Instrument Control GUI the CO
66. nt components of the instrument and numbers of the current masks in the cabinet It is updated after each cabinet exchange by the responsible technician or the instrument scientist in charge Three mask states can be selected from the pull down menu 1 No Mask IN USE all masks are in storage position This is the default configuration used for imaging 2 MAsk To FPU moves the mask that has been selected from the drop down menu Mask to Use into the focal plan This is the default set up for spectroscopic observations 3 MAsk To TURNOUT moves the mask out of the focal plane but not back to the storage position to save time This is needed for spectroscopic acquisition section 7 4 2 Calibration Panel The next panel in this GUI lets the user control the calibration unit It can be moved in and out from here and the current lamp status is shown To switch on the lamps an extra GUI Fig can be accessed via the OPEN GUI button There all lamps can be selected at once Note When asking to move the calibration unit in it sometimes happens that on the first click on IN following illegal error appears Problems with Calibration Unit device WebIO java lang IllegalMonitorStateException Do not worry Just try again Should the problem persists so ask your LBTO support astronomer to LUCIFER User Manual Issue 1 1 43 move the calibration unit in position from the corresponding engineering panel to which you do not have a
67. of this camera is optimal for the FWHMairy of the J band 2 0 pixel The H and K bands are oversampled 2 73 pixel and 3 73 pixel respectively It is currently not available The available modes are also given in Tab and Tab LUCIFER User Manual Issue 1 1 15 Figure 3 LUCIFER pupil image in K band On this image the swing arm sustaining the secondary mirror is visible PA 160deg as well as the displacement due to an internal pupil mis alignment 3 1 7 Filters Two filter wheels are placed in the convergent beam in front of the detector A total of up to 27 filters can be mounted The first filter wheel contains the narrow and medium band filters as well as a pupil viewer while the second wheel contains all broad band filters and the order separation filter for spectroscopy with the 200 H K grating Both filter wheels contain a blind filter Filter wheel 1 is always set before filter wheel 2 starts moving This is important to remember when wishing to avoid saturation e g before long spectroscopic integrations The characteristics of the currently available filters in LUCIFER 1 are given in Tab Appendix C contains details about the manufacturing specifications of the filters Tab 19 an equiv alent of Tab 7 with the filters for LUCIFER 2 Tab 20 as well as all the transmittance curves section C 1 3 2 Detector and Acquisition System Characteristics The detector is a HAWAII 2 HdCdTe detector whose main ch
68. ource catalog The image can be taken with LUCIFER or any other instru ment Within LMS images and catalogs can be downloaded from several servers LMS displays the following items as illustrated in Fig 1 FITS image or catalog positions projected on the LBT image plane 2 when the mask mode is initialized a the LUCIFER field white square b the back projection of the detector on the LBT image plane blue square c central field of low defocus inner white lines d field of unclipped spectra inner blue lines e area of the reference slits red rectangle close to the northern edge of the mask 3 when the mask is initialized and labeling is on default in addition LUCIFER User Manual Issue 1 1 27 a rotation angle and telescope pointing in the upper left corner b position of the six reference slits c d central wavelength at the northern edges of the unclipped area calculated wavelengths limits on the array at the two southern corners 4 when adding guide stars the guider patrol field X Skycat version 3 0 GD153 fits 1 File View Graphics Go Data Servers LUCIFERI Object dss18373 X 44 0 Y 17770 Value a 12 57 38 337 5 22 07 59 74 Equinox 2000 Min 5680 Max 27367 Figure 11 Typical display of the LMS tool To make sure that the slits are on the sources when observing the following rules have to be obeyed 1 The FIT
69. ow Band 2 2 66665 44 ba ma sa a a A 63 LUCIFER User Manual Issue 1 1 D Example of Scripts 65 6 Issue 1 1 LUCIFER User Manual List of Figures 1 LUCIFER optical layout 10 2 Transmission curve of the LUCIFER 1 entrance window The plot left shows the overall transmission inclusive the leak around 400nm while on the right a zoom over the NIR range is presented clusters have been highlighted pa 19 8 Sky backeroundl 4 844448 4 ee eee a tee as s sas 20 NIP OA eo 23 10 The AGw patrol field 25 RS Wliccscccrarrsrdsss nara rasa dr Se 2S 27 12 ___Offsets definition 28 13 LUCIFER broad band filters over atmospheric spectrum 32 bod eee ddr dS See dla e 33 15 OH spectrum in K band 34 16 Normalised sky spectrum in K band 36 17 Calibration lines 44 ss 444 44 eee AAR Dee we bee we eae EERO sa 39 18 Calibration lines iii wee a we LE eee ses 40 19 The LUCIFER Instrument Control GUI 42 20 The LUCIFER calibration unit GUI 43 21 The LUCIFER Telescope Control GUI 45 22 The LUCIFER Read Out Manager GUI 47 23 The LUCIFER GEIRS GUI 49 24 Wavelength depend
70. possible to take all flats in one sunset you thus have to prioritise your needs Should no flatfield be available at all so can you use the internal calibration unit to take imaging flats Note however that these are representative of true sky flats to within 10 and thus do not allow for good photometric data reduction Table 15 presents the count rate for imaging flatfields with the N3 75 camera When setting your calibrations script aim at a level of 15000 counts 20000 max 6 6 2 Night calibrations With the In principle there is no need to take any night calibration as the flexure compensation is active To be on the safe side however for spectroscopy short wavelength calibration and flat field might be useful to be taken overnight We provide here indication about counts rate per second for these calibrations For a quick over night calibration counts of the order of 200 300 ADUs are enough Calibrations with longer integration time are recommended to be performed during daytime Note For long slit spectroscopy most wavelengths calibrations can be performed using the atmospheric OH lines present in the spectra see Rousselot et al for a catalog of these lines Fig 16 shows an example of OH lines spectrum obtained with the 210zJHK grating the K filter the 1 slit and the LUCIFER User Manual Issue 1 1 35 Table 15 Count rates ADU s for internal flat fields with N3 75 camera Filter Halol Halo2 Halo3 Z
71. provide this This means that after a new start of the LUCIFER control software no information will be present Setting Up The Telescope To set a new target the user can use the text fields for target and guide star or a ASCII list which can be loaded via the LOAD CATALOGUE button in the Next Target sub panel The Input syntax for RA and DEC has to be in sexagesimal format like 46 Issue 1 1 LUCIFER User Manual RA 06 09 07 836 and DEC 24 22 32 35 for example The coordinates have to be in J2000 The ASCII catalogue for target and guide stars has to be formatted as follows using a pipe as the delimiter TARGETNAME RA DEC GUIDE NAME GUIDE RA GUIDE DEC PA RA_PPM DEC_PPM For example FS29 121 52 25 3835 02 23 19 5561GS_r14 3_d3 77_pos047 362121 52 36 538 02 25 52 21 45 23 00 302 98 For each target an appropriate guide star has to be defined by the observer As the telecope SW does NOT provide automatic guide star selection the user has to select the guide star s in advance It is possible to open several catalogues at a time By clicking on the desired line in the catalogue and using from the menu COMMIT gt COMMIT STAR sends the selection to the telescope GUI but not the telescope yet After the next target and guide star have been set additional telescope specific parameters can be changed The typical oberving setup is POSITION ACTIVE e ROT MODE Here the rotator mode can be set 1 POSITION 2 PARALLACTIC e TEL MO
72. r a filter the stronger is the influence of the Moon in the sky background H band sky emission is pretty independant of the Moon illumination but however strongly affected by variable atmospheric OH lines Under clear weather and comparable Moon illumination its value can fluctuate by a factor 2 on short time scale few tens of minutes The Mount Graham sky emissivity has been measured at 30 Issue 1 1 LUCIFER User Manual Table 10 Overview of all overheads times Action type Time sec Pointing correction 420 Pure preset 70 Collimation of active optics 135 Offset time Track mode 4 Guided mode active optics on 18 Motion of mask turnout to FPU 45 Read out time DCR mode 2 MER mode 10 Time to write a file 12 different occasions with LUCIFER under clear weather conditions using the N3 75 camera Table 11 presents some typical results where the limiting integration time has been rounded Table 11 Measured N3 75 camera sky emissivity and corresponding integration time to have the sky background reaching the linearity limit determined as two third of the full well No Moon 70 Moon illumination Filter Sky flux DIT lin Sky flux DIT lin e7 sec sec e7 sec sec Z 47 3900 120 1400 J 290 600 H 1315 140 2400 75 K 3250 50 4300 40 Ks 1640 110 H2 115 1600 Br gam 125 1400 Fell 97 1800 P_beta 42 4300 P gam 18 10000 6 5 1 Imaging During clear nights photometric standard stars have been observed i
73. rly outline which part of the set up corresponds to the different sub system telescope instrument detector For example all parameters relevant for the instrument set up have to be set within the _INSTRUMENT_SETUP section Any parameters not needed to be set can be commented out with a ff at the beginning of the line Should you wish to use a pre prepared script which contains a telescope set up but actually do not need it so can you comment the entire setion out by adding the symbol before the START_TELESCOPE SETUP and END TELESCOPE SETUP Note Altough the save path and filenames for the images can be specified within the scripts it is often more convenient to leave these two parameters out of the scripts or just comment them out In this case the values that are currently set through the READOUT GUI are used for the images name LUCIFER User Manual Issue 1 1 49 Lucifer Display Jvhwplx 1251 5v9b x04 Filev Colorv MagMode v SubArrays 2052 a J a Max Cut W E r a E F mm m l ul a LE A E Min cut E 1916 NOUS Pixel 1025 1024 2008 Radius lt 20 min max 1914 3950 2076 9 296 8 0 0 0 0 First masm azo Img sy o af Figure 23 The LUCIFER image display All reads made from a script will be automatically saved with the exception of the one taken during the ACQUISITION option in the OBSERVING_SETUP part of the script For the observer s conven
74. rrently no user friendly tool to perform this simple operation Monitor the guide star offset from the wfs on the acquisition images during subsequent presets When ever the guide star is more than halfway to the edge of the acquisition image you should consider repeating the above pointing correction procedure outlined above Please keep in mind that the more out of thermal equilibrium the telescope is the more often this will need to be repeated On well equilibrated stable nights you may only need to do this correction once after the beginning of the night Collimation Once the pointing has been corrected the guide stars should be within the capture range of the acquisition guiding and wavefront sensing AGw system that will be used to correct any remaining collimation errors in the telescope and maintain collimation throughout the night Any large focus offset at the start of the night should be manually removed by the telescope operator during the initial pointing correction above This will deliver an image to the AGw that can be guided on while the wfs collimates the telescope You may select any star for this initial collimation including an off axis guide star at your first science target If the telescope is far out of collimation at the beginning of the night or the seeing is poor gt 2 arcsec a brighter star R 10 12 would be useful until the point where it is saturating the guider or wavefront sensor A list of Persson
75. rvers to come prepared with pre selected guide stars suitable for their intended science targets Thus it is important to provide a guide star suitable for both guiding and wavefront sensing This is a function of the seeing and transparency of course but the nominal range for guide star R band magnitudes is 127 0 16 0 The USNO B1 catalog is a useful resource for locating guide stars and can be found at this URL http www nofs navy mil data FchPix cfra html 24 Issue 1 1 LUCIFER User Manual Because LUCIFER is bolted to the Auto Guiding and slow Wavefront sensing AGw unit they co rotate to follow the sky so the AGw has a fixed patrol field Fig with respect to the LUCIFER field of view Also the AGw unit is built onto an R theta stage which affects the layout of the guide star patrol field with respect to LUCIFER and therefore the position angles for your observations There are a few basic constraints to keep in mind The guide probe can move on axis but not past it The guide probe theta stage limits the X motion of the probe The focal plane is blocked at gt 330 arcsec radius There is vignetting from M3 at field angles above 3 5 arcmin off axis To avoid vignetting LUCIFER keep the probe gt 1 arcmin from the field edges oRWN RA Some details 1 The probe always appears to come down from above the LUCIFER field of view independent of position angle on sky because LUCIFER and the AGw are bolte
76. s and astigmatism as a function of elevation and temperature However the pointing and collimation models are strongly coupled by temperature effects on this asymmetric telescope As of writing Nov 2009 this is understood as unmodeled physical offsets of the optics induced by changes in temperature or temperature gradients These offsets in the position of the telescope optics generate offsets to both the pointing and the collimation of the telescope Since collimation corrections from the wavefront sensor are applied in a pointing free manner we are left with a net change in the pointing These thermal effects are under active investigation at the LBTO Until this is completed there are some steps that must be manually executed to achieve the overall initial collimation and pointing of the telescope and maintain it throughout the night Pointing correction Note At the start of the observing night a check of the pointing is always necessary How to check and correct the pointing if necessary Fig P 1 Be sure to have the telescope operator reset the mount encoders each day before the beginning of the night 2 Set up LUCIFER for imaging through a narrowband filter since the pointing stars are quite bright R 7 5 mag We usually use the N3 75 camera and the Brackett gamma filter 3 Point to a pointing star accurate positions and proper motions in open loop TRACK mode the rotator mode set to PARALLACTIC and with an angle of zero Thi
77. s aligns the LU 22 Issue 1 1 LUCIFER User Manual CIFER detector with the telescope elevation axis up down on LUCIFER and perpendicu lar to this left right on LUCIFER A list of pointing stars is available at the telescope in the IRTC notebook and the corresponding stars are in a catalog on the LUCIFER computer TargetsCoord PointingStars tab The stars to use are named WT10_ or ACT 4 Take a 2 0 second exposure with LUCIFER At this point you can iterate this step allowing the telescope operator to manually correct any gross focus errors until that is not the dominant collimation error then 5 Ask the telescope operator for the current values of TE and CA Also measure the approximate centroid of star on the LUCIFER image Lstar Ystar 6 Calculate the offset needed to move the star to the projected mechanical rotator center currently at pixel ref Yref 1014 1043 as follows CArew C Aola 0 12 x Tref Lstar IT Enew LE oa 0 12 x Yref Ystar Please note that this reference position may change slightly after each new installation of the instrument at the telescope Current values will always be available in the LUCIFER image headers in the keywords CRPIX1 xref and CRPIX2 Yref 7 Ask the telescope operator to implement these new values of IE and CA 8 Take another 2 0 second exposure to verify that the pointing star is indeed placed at the reference coordinates to within a few pixels There is cu
78. scope Setup PA 0 deg offset Name Name PA 0 CoordSYS RADEC 1 RA RA ROT MODE POSITION Side left D DEC DEC TEL MODE ACTIVE Movet REL RE E Load Catalogue Side EE Offset in arcsec RELATIVE Set Target Set Guide Star Set Telescope _Acquisition Telescope Specific Wait for Coll Status true SHIFT IMAGE Mos acqu Wait for Collimation ON ROTATE IMAGE Figure 21 The LUCIFER Telescope Control GUI provides all features to set up the telescope e Side This describes which mirror is in use Left LUCIFER1 Right LUCIFER 2 not available yet e Movetype Describes the type of offset relative or absolute Underneath these pull down menues buttons in a star pattern for 4 sky orientations are located allowing an offset in these direction The offset value in arcsec has to be typed into the appropriate text field in the middle of the pattern Pressing one of the orange orientation buttons will directly lead to a movement of the telescope Furthermore x and y offsets in arcsec can be typed into the bottom text field divided by a comma to move the telescope directly in two directions The small Comm IT button will also directly lead to a movement of the telescope Current Setup Information There are three sub panels describing the current values of the target guide star and telescope The current target and guide star information is stored locally since the telescope does not
79. sition The sky background emission can then be determined from the jittered frames if the local field is neither too crowded nor too dusty or will have to be estimated from sky frames obtained away from the region of interest and observed before and or after the science field 4 4 Spectroscopy Nodding In spectroscopy the object of interest is observed at different positions along the slit nodding 20 Issue 1 1 LUCIFER User Manual 600 T T T T T T T 1 6 mm H 0 Airmass 1 5 500 F 4 400 F a Photons sec nm arcsec m 100 b 0 ja Al A 1 M h tll 0 8 ul La2 1 4 1 6 8 2 22 2 4 Wavelength um Figure 8 Sky spectrum measured at Mauna Kea along the slit The sky removing is then simply done by substracting two different frames from each other For small size objects observed in long slit spectroscopy mode it is recommended to keep the nod size lt 30 to avoid being affected by the curvature of the atmospheric lines This is just to ease your data reduction Wavelength Calibration Below 2 2 um OH lines can be used for wavelength calibration Above that wavelength the OH lines are very weak In that case it is recommended to use the arc lamps of the calibration unit 3 3 4 5 Influence of the Moon Observing the near infrared the influence of the Moon illumination is small and can in many cases be ignored However for deep ima
80. software initial panel requests you to press on OK With the exception of the observer name that you can specify there to see it updated in the FITs header do not change any other of the settings Also Do NOT close any of the terminal window that opens automatically 7 2 Interactive Observing The instrument can be fully controlled by three GUls the instrument Fig 19 telescope Fig and readout GUI Fig 22 They all use the same kind of process by pressing the commit button after selecting the desired setup the software collects all properties from the GUI and builds up a setup which will be send to the appropriate software service and from there to the hardware The current setup is highlighted in green while the configuration selected to be set next appears in yellow This allows the user to track the changes of the instrument set up When a set up is being performed the full panel turns yellow Note Should accidently a wrong filter camera or grating have been selected press the current green button to discard your previous selection 7 2 1 The Instrument Control GUI This GUI gives the user access to all instrument relevant parameters of LUCIFER It consists of several sub panels which are explained here in more detail MOS Panel The use of masks in the focal plane is controlled from the left part of the GUI see fig 119 The current state of the unit is shown in the text fields Mos STATE and MASK IN USE During the movemen
81. t process a moving bar is visible Note In the case that the Mos STATE changes to UNKNOWN which will be color coded in red the instrument scientist has to be contacted immediately STOP doing anything with LUCIFER when this has happened The MOS state can be changed by using the two drop down menu one for the mask state Mask To Position and the one with the mask number to use Mask To Use The latter one shows the names 42 Issue 1 1 LUCIFER User Manual INSTRUMENT CONTROL OS INMALIZE UT 11 30 48 Version 0 987 RC 16 11 2009 MOS Camera Wheel Filter Wheel 1 Filter Wheel 2 HE nomaskinuse en sx N 30 clear unused Mask in use rating unit bin unused Mask to use NO MASK y 210 JHK J Mask to position NO MASK IN USE y Coo Mon y2 unused UPDATE 200 H K P_gam unused 150 Ks P_beta Ks Current none J low unused Calibration Unit Wavelength ym Desired A J high z Status OUT IN out wavelength tumi PV lens unused 1 2 3 4 5 6 Set Wavelength MM MMM A Ml Fell unused Open GUI Pupil Viewer Pupil Viewer Status OUT H2 K Flexure Compensation PV to position OUT Hel OrderSe Flexure Comp Status OFF E Em P Set Flexure Comp OFF v __Move Figure 19 The LUCIFER instrument control GUI allows classical access to all releva
82. th 150 lines mm 2 2 13 78 1 81 gt 2 400 4150 The gratings can be tilted in order to center a selected wavelength at the position of the long slits Table 5 defines the wavelength range covered for the tilt at the nominal central wavelength The gratings can individually be tilted by up to 2 5 degrees This allows a range of wavelengths to be centered on the detector as given in Table 6 for the N1 80 camera Note the 150_Ks grating can presently not be tilted and is fixed at Acen 2 15um 3 1 5 Pupil Viewer In combination with the N1 8 camera a pupil viewer is realized which allows to check the pupil image for vignetting and inhomogenous illumination Two lenses have to be added to the beam one in front 14 Issue 1 1 LUCIFER User Manual Grating Band Amin Acen Amar AA 210_zJHK K 2 025 2 200 2 353 0 328 210_zJHK H 1 541 1 650 1 743 0 202 210_zJHK J 1 169 1 250 1 319 0 150 210 zJHK Z 0 893 0 960 1 017 0 124 200 H K H K 1 475 1 930 2 355 0 880 150 Ks Ks 1 890 2 170 2 423 0 533 Table 5 Wavelength coverage for the gratings with the N1 80 camera at the nominal center wavelength For the N3 75 camera multiply AA by 0 48 Grating Band Arange 14 210 zZJHK z 0 87 1 02 210 zJHK J 1 05 1 28 210zJHK H 1 40 1 70 210 zZJHK K 2 10 gt 2 4 200_H K OrderSep 1 49 gt 2 4 Table 6 Wavelengths which can set at the center of the detector Careful the ranges given represent the physical lim
83. trol GUI this will always be applied Thus when offsetting after a rotation correction make sure to set this value to zero before commiting your set up Blind offset acquisition is feasible via scripts The acquisition procedure is the same as described above but on a nearby bright star At the end of the alignment procedure the offset onto your science target will be performed gt you preset onto the reference star and provide the offset to move from the reference star to the faint target An example of script on how to do this is given here The Acquisition option allows to have a read of the telescope automatically performed but no image saved from the script once the collimation of the telescope has been reached Then the script pauses as long as you do not explicitly tells it to continue This paused time is then used to perform the alignment on the reference star Once this is finished let the script continue 4 finish it performs the blind offset and takes an image START_INSTRUMENT_SETUP CAMERA N3 75 FILTER blind K GRATING_UNIT mirror MASK NB4 MASK_POSITION mask_in_fpu FLEXURE_COMP off END_INSTRUMENT_SETUP START_TELESCOPE_SETUP TARGET_NAME MyTarget TARGET_COORD 11 22 33 44 55 00 7 GUIDE_NAME GSC GUIDE_COORD 11 22 32 9 44 55 01 2 ROT_ANG 12 5 ROT_MODE position TELESCOPE_MODE active END_TELESCOPE_SETUP START_READOUT_SETUP DIT 0 NDIT 30 NEXPO 1 ROE_MODE 02dcr SAVE
84. turnout position via the Mask_to_turnout command in the MOS panel e Once the collimation of the telescope is finished take an acquisition image of the field of interest e Center your object behind the mask using the SkyCat display e Make a read from the Readout Manager GUI and check your alignment in the SkyCat display take a through slit image e Once satisfied with the alignment start your spectroscopic script that includes the instrument setup mask in FPU grating in position When performing an acquisition before deep spectroscopic observations avoid saturating the detector and thus creating persistance effects Should the acquisition image contain bright stars it is recom mended to perform a number of short detector reads DIT 2sec with the blind filters for a minute or two before starting the long integrations The details of the alignment procedure differ a bit depending if only long slit or multi object spec troscopy is to be done as detailed hereafter Long Slit Spectroscopy Long slit acquisition is easy you wish to put one or more objects behind the long slit For a single object a simple offset will be enough in case of two or more aligned objects to be put behind the mask you may wish to adjust the position angle slightly The through slit image is needed as reference to move the object to the correct position Once this image has been saved put it as Bias image in skycat option reacheable from the
85. utting The grb file is used for the mask cutting machine available in Munich the _v2 grb file can be read by the LBT mask cutting machine 6 2 Offset and position angle definition On the LUCIFER images for a position angle null North is towards the top of the image while East is towards the right unlike the typical orientation of astronomical images The position angle you give is however defined the classical astronomical way from North to East and given in degrees All offsets are defined in arcseconds The telescope can be offsetted either in RA DEC the coordinate system is then defined as RADEC or along the lines columns of the detector the coordinate system is then DETXY The latter is very useful for e g long slit spectroscopy One also has to define the type of offset cumulative the offset type is then relative and one moves relative to the last position or absolute where all offsets refer to the original position When offsetting the RADEC one basically tells the telescope where to go the object on the detector will move in the opposite direction Offsets in DETXY defines where the object will move on the detector The active optics duty cycle is typically of 45 seconds it is therefore recommended to spend at least one minute per position after before offsetting Figure 12 Illustration of the star motion defining a relative offset pattern in RADEC left or DETXY right For offsets in DETXY coordinates

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