SAO Wide-field InfraRed Camera (SWIRC)
Contents
1. Filter Shutter Azoff Eloff CURRENT Il COMMANDED j I Startup Standard Ops Catalog Ops Dither Tool Obslog Tool Start Stop l mmt ir __swire swire 2005C SA0 14 SAO 14 B Patten W Browr Patten jesesons Very similar to the Standard Ops window Catalog Ops allows one to observe using a dither catalog 1 Clicking on the DITHER button allows one to load a dither catalog Alternatively clicking DITHER and then Cancel will remove the current dither catalog 2 If the filter is not specified in the dither catalog select a filter with the drop down menu 3 If exptime is not specified in the dither catalog enter in the exposure time 4 The first and last set the number of images to take Setting first 1 and last 9 will do the first 9 positions in a dither catalog for example 5 Press Go to start the dither sequence Pause Queue works the same as before Other points 6 The Title button allows you to enter the title located in the fits image header before a sequence is started however you will still be asked to confirm the title at the beginning of the next observation 7 The red Clear button may be used to clear a hung exposure but if you are in such a situation closing mice and re starting mice is a better solution 8 The Pause Expo button has no functionality for SWIRC DITHER CATALOGS IMPORTANT2. measured in degrees east of north 0 The filter and exposure time used for a dither sequence are the filter and exposure time set on the MICE window Alternatively you can add columns filts and exptime to set the values yourself For example azoff eloff filts exptime 0 0 H 15 300 0 H 15 0 0 J 10 300 0 J 10 This dither catalog will cause SWIRC to take a 15 sec H band image ON and OFF source followed by a 10 sec J band image ON and OFF source To repeat a dither sequence on a slightly offset position use the paddle tool to offset your pointing in RA DEC coordinates not INST coordinates and then run the dither sequence again DITHER TOOL MICE can generate dither catalogs with its Dither Tool tab a Enter the size of the x and y offsets E Instrument Servers Camera Servers Telescope b Enter the number of x and y offsets Chip temp ElcolSec Image Type Exposure ExpStatus QueStatus an a c Enter the desired filter and exposure time or EG coon sean leave these blank so that the dither catalog will look to the current values on the MICE window steno stanaaes Ops Cataig Ops omer Teo 10g Toot sarrsop d Press Save and enter the desired filename Jf Ee es n e You can now press View to review the generated catalog OBSLOG TOOL MICE automatically generates an observing log Use the Obslog Tool tab to add comments and view the postscript file You can also run stand alone versi
3. be down a Make sure the instrument power is on and the Ethernet cord plugged in b Ask the operator to make sure the cell rack is on 3 On rare occasion the image readout becomes scrambled or has weird lines To fix this a Cycle the power on the instrument b Re initialize the electronics by pressing the ccdswirc button on the MICE Start Stop tab VII Reduction Scripts old Preliminary data reduction may be done on the computer lewis Data reduction scripts are in various stages of refinement On lewis the procedure is 1 Run cl from the swirc home directory to start IRAF 2 cd data crunch SWIRC year date 3 Outside of IRAF type sethead fits BPM mask pl so IRAF knows to use the mask file The file mask pl and J amp H sky flats are located in the directory home swirc Cal 4 epar imcombine and set masktype badvalue and offset none 5 Combine your darks and flats as your normally would 6 In IRAF type swirc 7 epar swircreduce and set the dark subtraction flatfield sky subtraction and mask params Do not use the WCS refinement or alignment this part does not work on cracker 8 Run swircreduce from epar with a g command 9 When swircreduce is finished look at the msk fits files for bad features On the Unix command line you can 10 Fix bad bias variations on channel 4 5 with swirccolfix ___ fits 11 Fix the pinwheel looking readout bias variation with swircfix ____fits 12 Ru
4. in a continuous clear mode in between exposures Readout 32 channels 8 channels per quadrants Readout time 0 7 sec per readout 8 sec total overhead per exposure Exposure times Must be integer seconds gt sec Filters J H and two dark positions D1 and D2 Filter focus offset from wavefront sensor focus H 15 micron J 15 micron Optical Layout detector filter dewar window 30 LAYOUT TUE TUL 1 Z BS C ZREN E F2 WRT D R CONFICURATION 1 DF 2 HI Quick Start Introduction MICE MMT ICE is a graphical interface for observing with SWIRC MICE allows you to control filters exposures times and dither sequences and is run on the computer clark MICE automatically displays the current image to a ds9 frame 1 and display the difference of the current and previous image to a ds9 frame 2 Status displays monitoring the telescope and instrument are provided on the monitor hudson located above clark To observe on clark 1 Log into clark mmto arizona edu with username swire password located in the drawer 2 At a UNIX prompt run go go to bring up the MICE interface and status display windows 3 On the MICE start tab click the Home Filter Wheel button and wait 3 sec for Homed to turn green 4 Click the Standard Ops or the Catalog Ops tab 5 Select your exposure time filter and optionally a dither catalog 6 Start observ
5. ELNAME should be set to mmt_ir to enable communication with the telescope 2 The PROPID and P I are selected from pull down menus OBSVRS are entered by the user 3 The FileRoot is taken from the MMT catalog object column and cannot be edited Note that images are titled fileroot fits and are located in data ccd SWIRC year date where year date looks like 2005 0924 To observe 4 Select the Filter from the drop down menu 5 Clicking the ConfigObs button will immediately change the filter otherwise the selected filter will be moved into position at the beginning of the next observation 6 The drop down menu on the lower left selects what type of image to take Science images should be object Selecting dark will automatically move the filter wheel to a dark position and name the fileroot dark 7 Enter in the first and last numbers of the sequence 8 Enter in the exposure time 9 Press the green Go button to start 10 Beware the POP UP window type the object title and press return to start the sequence 11 If you want to pause abort or change the length of the sequence press the yellow PAUSE Queue button and then take the appropriate action with the buttons at the bottom of the screen 12 Pause Expo does not work with SWIRC DITHERING Instrument Servers Camera Servers Telescope Chip temp 75 198 EleolSee Image el Exposure ExpStatus QueStatus ag P
6. INFORMATION Dither catalogs are starbase tables http www cfa harvard edu john starbase starbase html with two primary columns azoff and eloff Azoff and eloff are offsets in the x and y directions respectively in instrument pixel coordinates That is azoff and eloff do not correspond to the cardinal directions east or north unless the MMT instrument rotator is set to track north The format of the starbase table is a header line titled azoff lt tab gt eloff a separator line lt tab gt and then lines with offsets in units of in units of arcseconds Everything must be separated by tabs For example azoff eloff 60 60 60 60 60 60 60 60 Loading this dither catalog setting first 1 and last 4 and pressing Go will cause SWIRC to take 4 images at the indicated offsets from the catalog position To take a second series of 4 images with the same dither catalog but not centered on the catalog position use the paddle to offset in RA DEC coordinates not INST coordinates and then repeat the observation To re iterate dither offsets are applied in instrument coordinates and do not alter the angle of the MMT rotator The operator normally sets the MMT rotator so that it tracks North up Thus in normal operation the example dither catalog offsets are purely north east south west If you wish to map at a different angle simply tell the telescope operator to have the rotator track at your desired angle
7. SAO Wide field InfraRed Camera SWIRC User s Manual Warren R Brown Version 17 Nov 2005 TABLE OF CONTENTS I The SWIRC project II Instrument Characteristics III Quick Start IV Details on the MICE Interface and Dither Catalogs V Tips for Observing at the MMT VI Troubleshooting VII Reduction Scripts old I The SWIRC project SWIRC is a J and H band imager for the f 5 cassegrain focus of the MMT The goal of the instrument was to deliver quickly a wide field of view instrument with minimal optical elements and hence high throughput The trade off was to sacrifice K band capability by not having an internal cold Lyot stop SWIRC has two filters J band 1 2 um and H band 1 6 um plus dark slides There is an available filter slot for a user provided filter The detector is a 2048x2048 pixel Hawaii 2 HgCdTe engineering grade array with good cosmetics purchased as part of the MMT Magellan Infrared Spectrograph project SWIRC s detector mount electronics and observing software are prototypes for the MMT Magellan Infrared Spectrograph SWIRC was proposed in 2003 May and commissioned 2004 June 30 July 6 Sustained seeing of 0 4 arcsec FWHM was observed during commissioning Throughput is 2 5 3 times that of FLAMINGOS on the MMT An exposure time calculator and this manual are available from SWIRC s homepage http www ctfa harvard edu swirc SWIRC was made possible by significant efforts fr
8. buttons do not necessarily mean that things are working if power has been cycled on the instrument the top two servers must be re started cB bell Bas Camera Servers Telescope Chip temp f8 EleolSec Image Type object Exposure ExpStatus i QueStatus Filter Shutter Azoff Eloff CURRENT COMMANDED Startup Standard Ops Catalog Ops Dither Tool Obslog Tool Start Stop Swirc servers Swirc interfaces mc9 Log mountdisplay Log icedisplay Log expdisplay Log paddle Log fwdisplay Log dealgui Log 1 ccdswirc re starts the detector server and re initializes the electronics Use this if the instrument has been turned off and turned back on 2 hskswirc re starts the housekeeping temperature monitor server Use this if the instrument has been turned off and turned back on 3 fwswirc re starts the filter wheel server After pressing this home the filter wheel Startup tab 4 crunchswirc and archiveswirc are the two processes that archive images to the local disk farm and to the CfA respectively 5 The gray buttons on the right column allow you to re start any status display window and MICE itself V Tips for Observing at the MMT 1 Getting Started a Password located in the drawer under the table at the observer station b Use the machine hudson to display status windows c Reset the image sequence number 1 close mice using the close button on the upper lef
9. ing At the end of each night 1 Fill SWIRC dewar takes 10 minutes 2 Note that images are automatically archived via ftp to the CfA and will be available to the user at the end of the run Details on observing Section IV discusses MICE in detail Section V gives tips for observing at the MMT Section VI gives troubleshooting advice IV How to Use the MICE Interface and Dither Catalogs STARTUP 1 To set the file counter to 1 edit the sequence number in IRAF obspars before running mice 2 Run go go or domice to start a Mice window 3 Mice will start you in the Startup window shown below IMPORTANT press Home Filter Wheel to home the filter wheel iv mice 4 Note that the area above the Startup and other tabs shows status displays no information can be entered in those boxes OBSERVING _ Instrument Servers Camera Servers Detector Up Chip temp ElcolSec p temp Image Type Exposure ExpStatus QueStatus Filter Shutter Azoff Eloff CURRENT COMMANDED Jj jf Startup Standard Ops Catalog Ops Dither Tool Obslog Tool Start Stop mmt_ir __swire swire 2005C SA0 14 SAO 14 B Patten W Browr Patten poson 2749 993 1 NAMI S ABORT READO0T RESME ena eer eee eee eae The Standard Ops window lets you take a series of exposures at a given position 1 T
10. lats for each filter in the time available 3 Typical Observing Procedure a Take darks b Let the operator know you want to take sky flats so the telescope is ready to go at sunset c Take sky flats d Go to your first target e About 45 min after sunset it is dark enough to use the wavefront sensor to focus the telescope f Optional you can more exactly align the optical axis to the center of SWIRC i Take a short exposure with SWIRC ii Open the fix pointing task under the Observe menu on ds9 iii Drag the red current circle onto the star iv Click OK for a hexapod move v Ask the operator to write down this offset and apply it in the future otherwise the next wavefront sensor focus will eliminate the offset g Go to your target h Ask the operator to track North for SWIRC 180 in the South 0 in the North i Observe Be sure to tell the operator to set focus for your current filter h If you repeat dither patterns offset the central pointing in RA DEC coords with the paddle tool E AZ fo z u AZIEL v RADEC INST GUIDE 4 Focus a A wavefront sensor focus is generally required i if moving to a different part of sky ii if the temperature changes by more than 1 degree F or iii if more than a couple hours has elapsed since the previous wavefront focus b A wavefront sensor focus takes 10 minutes which is a significant investment of time c Moni
11. n imwes on the msk fits files using the script runimwes sc 13 Back in IRAF epar imcombine and set offset wcs 14 Run imcombine to stack the msk fits files
12. om the following people Principal Investigator Dr Warren Brown Co Investigators Mr Stephen Amato Dr Matt Ashby Ms Emily Bowsher Dr Giovanni Fazio Dr John Geary Dr Joe Hora Dr Brian McLeod Dr Tom Megeath Dr Michael Pahre Dr Andy Szentgyorgyi Dr Steven Willner Mr William Wyatt Mr Joseph Zajac II Instrument Characteristics Secondary f 5 Detector 2048 x 2048 pix HgCdTe Hawaii 2 Pixel scale 0 1500 arcsec pix Field of view 5 12 x 5 12 arcmin 2 Electronics gain 4 0 e DN Read noise 31 e Full well 190 000 e or 48 000 DN Linearity Linear to 40 000 DN linear to better than 0 1 Dark current 16 e s pix Bias drifts The bias changes by 400 DN over 20 sec thus darks must be taken for every exposure time lt 20 sec Detected electrons for 15 mag star Vega relative J band 40 000 e s H band 38 000 e s Sky background J band 870 e s pix 14 7 mag arcsec 2 H band 3400 e s pix 13 4 mag arcsec42 Exposure time for sky to reach 20 000 DN half the linear regime J 90 sec H 20 sec Distortion Very small predicted 0 01 center to comer Cross talk None between quadrants very little in channels within a quadrant Known problem Channel 4 5 suffers from RMS 19 DN bias variations Images with the Hawaii 2 are taken by differencing a pair of non destructive reads There is no shutter in SWIRC rather each line is cleared before being read the first time The Hawaii 2 is put
13. on from the command line with comment Do not use obslog and comment simultaneously TA iv comment ja x Instrument Servers Se E E Telescope Sort by Time Ascending me Chip temp Etcolsee o Allen 1040 Les Image Type Exposure ExpStatus Questates o Allen3 1039 ume Piler Shutter Azoff Eloff o Allen3 1038 il Type t CURRENT i i o Allen3 1037 Ra fpoiaaeace COMMANDED o Allen3 1036 EGR ete ste ne o Allen3 1035 Dec o Allen3 1034 sien standard ops Cetaiog ops commer Too Coniog tox sns o Allen3 1033 lt form fly 2 o Allen3 1032 a o Allen3 1031 Comments Miles EEJ o Allen3 1030 mimes psa o Allen3 1029 Sort by Time Ascending Type o Allen3 1028 ten ie EE Ras o Allen3 1027 a ba Sead g Der fna o Allen3 1026 o Allen3 1025 Comments o Allen3 1024 o Allen3 1023 o Allen3 1022 i hs _Seve changes O ERT 1 To add a comment a Click a file b type the comment in the Comments field c press the Save Changes button or click to another file 2 To generate and view the postscript logfile press the SAO symbol on the lower right 3 Note that the log is generated with LaTeX so avoid unhappy LaTeX symbols amp START STOP MICE provides you the ability to re start all of the instrument servers and all of the status windows via buttons on the Start Stop tab Server buttons are green when they are running red when they are not running Note that green
14. t corner of the window ii type obspars in IRAF and set the sequence number to the desired value iii restart mice with domice d Data on lewis and clark are located at data ecd SWIRC 2 Calibrations a Darks i Irecommend taking darks for each exposure time that you use ii You can take darks in the afternoon iii The darks are temperature sensitive so make sure that the instrument has been powered on for at least 2 hours ambient chip temp is 83 84 K iv Throw away the first 2 or 3 darks in a sequence Amps on the HAWAII 2 device warm up when used thus the first few darks have spurious statistics until the chip has equilibrated to the cadence of exposures you are taking b Flats i Flats are done as sky flats ii Sky flats are taken in a 10 minute window starting 5 minutes after sunset or before sunrise iii Set object type to skyflat shortly after sunset iv Ask the operator to run the slew authorization program v Take one exposure which will set the telescope at the point in the sky with the least gradient vi Change object type to object vii Take 10 exposures in each filter once the images are no longer saturating viii Saturating does not harm the detector ix The J and H filter come out of saturation around the same time x Offset a couple arcmin between each exposure using the paddle tool x1 Make sure telescope tracking is on during sky flats xii You can probably get 10 f
15. tor the FWHM and PSF shape of stars in your images as they are displayed in the ds9 window If the PSF no longer looks peaked or the FWHM changes substantially you require a wavefront sensor focus d Remember each filter has a focus offset from the wavefront sensor 15 for H 15 for J 5 Lightening Protection a Turn off instrument power press the switch on the black power strip to the OFF position b Physically unplug the power cord on the cable drape c Unplug the ethernet cord from the black EDAS box on the instrument 6 Maintenance a Refill the dewar each morning b Filling dewar takes 10 minutes c The dewar is very messy the dewar is not full until a good fountain of LN2 comes out d The fill tube has a quick release connector that freezes wait 10 minutes before removing it e Replace the little red cap onto the fill tube to prevent ice build up on the fill tube f Dewar hold time is 36 hours with the power on 48 hours with the power off VI Troubleshooting 1 Most problems are solved by closing the MICE window and running domice again Examples of such times are when a the exposure status says exposing or readout but nothing is happening b the first and last boxes or the exptime box are grayed out instead of blue as happens after trying to cancel an exposure 2 If you have problems starting the instrument servers the Ethernet connection to the instrument may
Download Pdf Manuals
Related Search