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(IRCS) User Manual

1. gt no e co zs gt 00054666 00019295 01118321 wane ait MANA GHOO T 000694261 NE eeLET 0008 048 90060962 GHOC T 0006 4056 WSIYD x TI 459 Kjryuopt TT0Z 99 ET 22 11 90 peooppeedgdsooKd LHOdXAVI ZA JVUI OVON SUOIISSUL qysuopoAe M 00081 00021 00091 00091 CHOS c GHOS c6 I 0000 70041 0141 E mrs 0009 T5491 0000 ES 0009 94T6T GHOO S m so ES 2c co c gt 0006 6668 0009 6164 007 16691 09 A 9400 I 000905057 9486 I 940 I gt e a gt NO NV H NSIAD TIJIV H19S Man 1102 45 62 01 62 61 nup 122280509944 T PT ZA JVHI OVON 6 019 UIA IAR Y 00096 000Vc UU UL 00066 00016 00006 0000G 0000 0009 2608 0005 2961 0005 T6066 M 0002 T2661 S300 L vo e es gt 006 BETES 0001 OST 0002 68070 GHOG L 0008 T660c SH00 6 09 6 0006 12908 NO UV X NSIUD x TI JIV 3495s JIFUOPI TTOG INY 2T 69 90 60 141 eoop ucirypo doos s27 LIOAXAPT ZA AVAI OVON 8 6 qysuo oAeM 0009 00GCY 0000F OOGLE 000G 00Sc 00006 0UG Z 000 0006 GORGE 0000 66616 0008 96462 0006 840 00001 c gt DD e gt c gt
2. 32 43 2 ABBA shit DOE soc ee X A Ar 32 4 3 3 Object Sky Object 33 4 3 4 Slit scanning Ls 204 4e ae Rae R RETA RS ee 33 4 4 Overheads and total observing time calculators 33 4 4 1 Common overheads 33 S O A 33 4 4 3 Polarimetry a special case 22e 35 4 5 Spectral format calculators 35 46 OREM TELE 26 m er Ale aides Re cgay Da Wea egit od den 36 406 1 List of targets de mom Psa Sie MS DA ete 36 4 6 2 Observing procedure 37 5 Appendix 42 5i Bits header 24 4 gant Le Mar a ne bin Phe an date dne i bete 42 5 2 OH emission lines 50 5 3 Ar lines atlas for grism spectroscopy 58 Preface This manual was prepared by a user for a user In its current version this document is intended to help in preparation of the proposal for the IRCS instrument and then to perform the observations It may not immediatelly contain all required information so you may find blank spaces and signs but we work to include all that is necessary We appreciate your feedback If you think some important information are missing let us know and we ll try to include it in the future KGH Chapter 1 Introduction 1 1 Scope The scope of this manual is to cover all aspects of the
3. HH MM SS SSS RA pointing DEC 07 00 53 88 DD MM SS SS DEC pointing RA2000 10 56 28 557 HH MM SS SSS RA 12000 pointing DEC2000 07 00 53 88 DD MM SS SS DEC J2000 pointing AZIMUTH 159 279 Azimuth angle of telescope pointing ALTITUDE 76 2602 Altitude angle of telescope pointing ZD 13 7398 Zenith Distance at typical time LONGPOLE 180 0 The North Pole of the standard system RADECSYS FK5 Equatorial coordinate system CRPIX1 512 5 Reference pixel in X pixel CRPIX2 512 5 Reference pixel in Y pixel CRVAL1 164 11898750 RA dg of CRPIX1 reference pixel X CRVAL2 7 01496649 DEC dg of CRPIX2 reference pixel Y CDELT1 0 00003194 X Scale projected on detector dg pixel CDELT2 0 00003194 Y Scale projected on detector dg pixel FOC POS Nasmyth IR Focus where instrument is attached 43 TELFOCUS Nasmyth IR Focus where a beam is reachable CAS TAVE Cassegrain Enclosure Average Temperature FOC VAL 0 151716 Encoder value of the focus unit AIRMASS 1 0294 Averaged Air Mass INSROT 11 4894 Instrument rotator angle INST PA 0 270 Instrument rotator position angle AUTOGUID OFF Autoguiding on off PROJP1 0 0 Projection Type of the first axis PROJP2 0 0 Projection Type of the second axis PC001001 0 999989 Coordinate translation matrix PC001002 0 004712 Coordinate translation matrix PC002001 0 004712 Coordinate translati
4. PIXEL 0 020 PIXEL SUPPORT PLATE Figure 3 1 Layout of the fore optics and the camera section of the IRCS 10 Figure 3 2 Example of a raw IRCS AO188 image from the camera section A group of bad pixels near the center and a single star right to it can be seen The optical layout of the camera section together with the fore optics is presented in Figure 3 1 The Figure 3 2 shows an example of a raw IRCS image in the 20 mas pix scale The default orientation is North is left and East to the bottom with the position angle PA set to 0 With PA 90 N is up and E to the left 3 1 1 Detector The imaging section camera is equipped in 1024x1024x27um ALADDIN HI InSb detector Its basic characteristics are summarized in Table 3 11 In common with all ALADDIN arrays there is some latency For the current IRCS camera array latent images are seen at the level of 0 1 if the wells have been more than half filled For this reason it is recommended to keep your counts well below the saturation level The detector also has a number of bad pixels concentrated mainly at the edges but also close to the center in the first quadrant Fig 3 2 They can be corrected using the bad pixel mask http www naoj org bserving Instruments IRCS camera cam badpix pl Or cam badpix coo If you need the old parameters before July 2005 when IRCS was mounted on Cassegrain focus please see http www naoj org bserving Instruments IRCS para
5. 46 D_LWADS1 384000 LOWFS ADC prism 1 position microstep D_LWADA2 0 LOWFS ADC prism 1 position deg D_LWADS2 384000 LOWFS ADC prism 1 position microstep D_LWADFC 1 LOWFS ADC prism angle correction factor LWADRA 05 01 06 3 LOWFS ADC tracking right ascension J2000 D_LWADDC 45 16 30 LOWFS ADC tracking declination 72000 D LWADPA 50 LOWFS ADC tracking position angle deg D_LWABS NONE LOWFS acq cam BS position D LWABSP 30 18 LOWFS acq cam BS position mm D_LWAF1 NONE LOWFS acq cam filter wheel 1 state D_LWAF1P 0 LOWFS acq cam filter wheel 1 pos deg DLWAF2 NONE LOWFS acq cam filter wheel 2 state D_LWAF2P 0 LOWFS acq cam filter wheel 2 pos deg D_LWAP2 7 LOWFS AP2 name D_LWAPS 5 0691 LOWFS AP2 size arcsec LWPBS NONE LOWFS pupil cam BS position D LWPBSP 30 61 LOWFS pupil cam BS position mm LWLAZ NOBS LOWFS LA focus stage position LWLAZP 5 2 LOWFS LA focus stage pos mm D LWLAF CLOSE LOWFS LA filter wheel position D LWLAFP O LOWFS LA filter wheel pos deg D LWLASH CLOSE LOWFS LA shutter state OPEN CLOSE D LWAPDA 0 16 LOWFS APD Average Counts kcps elem D VMDRV 701 VM drive ON OFF D VMVOLT 2 VM voltage V D VMFREQ 1000 VM frequency Hz D VMPHAS O VM phase deg LOOP ON RTS Loop state ON OFF D DMGAIN 5 RTS DM gain D TTGAIN 0 001 RT
6. 47556 0 05 355 7 191 9 38 1 47724 0 15 401 1 195 2 38 1 47837 0 15 431 8 197 4 38 1 47998 0 30 475 7 200 6 38 1 48057 0 26 491 9 201 8 38 1 48330 0 62 567 2 207 4 38 1 48644 0 20 654 8 213 9 38 1 48862 0 01 716 3 218 6 38 1 48877 0 78 720 6 218 9 38 1 49091 0 10 781 5 223 6 38 1 49319 0 26 847 2 228 6 37 1 50261 0 01 26 5 249 1 37 1 50528 0 01 93 9 253 8 37 1 50555 1 95 100 8 254 3 37 1 50640 0 01 122 3 255 8 37 1 50689 0 66 134 8 256 7 37 1 50882 0 23 184 1 260 3 37 1 51137 0 10 249 8 265 0 37 1 51870 0 38 441 7 279 1 37 1 52410 1 41 586 4 290 1 37 1 52878 0 58 7143 300 0 37 1 53324 1 15 838 5 309 7 Continued on next page 52 Order A um Intens X pix Y pix 37 1 53953 0 40 1017 9 324 1 36 1 54621 0 10 72 2 337 0 36 1 54744 0 01 102 5 339 2 36 1 55008 0 20 167 9 343 9 36 1 55098 0 25 190 3 345 6 36 1 55179 0 20 210 6 347 1 36 1 55404 0 55 267 1 3513 36 1 55462 0 01 281 7 352 4 36 1 55702 0 15 342 6 357 0 36 1 55977 0 70 4129 362 3 36 1 56313 0 01 499 8 369 0 36 1 56316 0 35 500 6 369 1 36 1 56550 1 05 561 8 373 8 36 1 56570 0 01 567 0 374 2 36 1 57025 0 28 687 6 383 8 36 1 57603 0 10 844 0 396 4 36 1 57821 0 15 904 0 401 3 35 1 58973 0 10 56 5 425 2 35 1 59159 0 01 101 0 428 5 35 1 59726 0 50 238 1 438 9 35 1 60308 1 53 381 6 450 0 35 1 60798 0 65 504 6 459 7 35 1 61286 1 71 629 3 469 7 35 1 61947 0 63 801 8 483 9 39 1 62354 1 27 910 4 493 0 34 1 63418 0 12 3 2 515 7 34 1 63513 0 65 25 1 517 3 34 1
7. 5 327 2 27 2 10680 0 22 448 3 349 7 27 2 10966 0 01 506 3 354 0 27 2 11057 0 01 524 8 355 3 27 2 11159 0 24 545 7 356 9 27 2 11561 0 12 628 6 363 1 27 2 11766 0 38 671 3 366 4 27 2 12325 0 15 789 1 375 5 27 2 12497 0 41 825 8 378 3 27 2 12791 0 05 889 1 383 3 27 2 13180 0 01 973 9 300 0 27 2 13260 0 16 991 5 391 4 26 2 17111 0 25 130 5 448 8 26 2 18022 0 70 301 9 461 4 26 2 18735 0 35 438 9 471 8 Continued on next page 57 Order A um Intens X pix Y pix 26 2 19556 0 90 600 3 484 2 26 2 21255 0 80 947 7 512 2 25 2 25180 0 25 21 2 572 2 25 2 27420 0 15 426 9 603 2 5 3 Ar lines atlas for grism spectroscopy Following are graphs showing the Ar lines for wavelength calibration of grism spectroscopy The first two are for low resolution grisms then plots for the high resolution follow They are supplemented by atmospheric transmittance plot in the L band where the calibration can be based on several telluric lines In some graphs lines on the redder part may not be marked but they can be identified on the next spectrum 58 49 01 Dec 2011 AR ON identify gsGRJH Ar 11 GRISM JH OQUE Coney DR aw ell 11 mean MM DSG QE 17500 20000 22900 15000 Wavelength angstroms 008 LOSE ll qucm 000 0966 Ae ae 194121 QUT 11140011 0002 T6711 M 00089490
8. 64764 0 01 53 4 528 6 34 1 64790 0 50 59 6 529 1 34 1 65023 0 75 1149 5332 34 1 65539 0 30 238 9 542 6 34 1 65863 0 01 317 8 548 7 34 1 66110 0 10 378 5 553 5 34 1 66892 0 01 574 4 569 1 34 1 66921 2 30 581 7 569 7 34 1 67088 0 83 624 3 573 1 34 1 67325 0 30 685 3 578 1 34 1 67636 0 15 766 1 584 8 34 1 68405 0 30 970 6 602 1 33 1 69551 0 52 6 3 625 8 33 1 70088 1 80 129 8 635 3 33 1 70783 0 70 292 6 648 1 33 1 71236 1 20 400 7 656 8 33 1 72104 0 36 612 6 674 3 33 1 72486 0 70 708 0 682 3 Continued on next page 59 Order A um Intens X pix Y pix 33 1 72829 0 18 794 9 689 8 33 1 73309 0 32 918 5 700 5 33 1 73511 0 20 971 3 705 2 33 1 73597 0 20 993 9 7072 32 1 75013 0 27 42 6 735 6 32 1 75060 0 08 53 0 736 4 32 1 75294 0 08 105 8 740 5 32 1 76532 2 00 387 9 763 6 32 1 76718 0 70 431 3 767 2 32 1 76984 0 18 493 8 T72 5 32 1 78114 0 08 766 3 796 1 32 1 78803 1 20 938 3 811 5 31 1 80679 0 18 47 0 849 7 31 1 81185 0 50 156 7 858 7 31 1 82110 0 01 361 6 876 0 31 1 82542 0 05 459 3 884 4 31 1 83528 0 01 687 7 904 7 31 1 83646 0 01 715 5 907 2 31 1 84004 0 01 800 8 915 0 31 1 84017 0 01 803 9 915 2 31 1 84023 0 01 805 4 915 4 31 1 84335 0 01 880 7 922 3 31 1 84595 0 01 944 2 928 2 K set 29 1 89901 0 01 22 8 110 5 29 1 90484 0 01 135 4 118 4 29 1 91141 0 01 264 2 127 6 29 1 91932 0 01 422 1 139 1 29 1 92503 0 32 538 1 147 7 29 1 93501 0 25 745 6 163 4 29 1 93992 0 01 850 0 171 6 28 1 96990 0 15 79 8 218
9. 918 2 286 3 51 1 09763 0 35 110 8 286 3 51 1 10103 0 10 232 4 295 6 51 1 10303 0 28 304 8 301 2 51 1 10733 0 05 463 1 313 8 51 1 10903 0 15 526 7 318 9 51 1 11413 0 02 721 0 334 9 51 1 11563 0 05 779 3 339 8 50 1 13134 0 12 531 4 386 5 50 1 13314 0 15 598 1 392 0 50 1 13544 0 10 684 3 399 3 50 1 14364 0 40 1001 1 426 7 49 1 14364 0 40 152 1 425 4 49 1 15395 0 32 514 2 454 9 49 1 15665 0 02 612 1 463 2 49 1 15925 0 35 707 9 471 5 49 1 16285 0 12 842 7 483 3 49 1 16515 0 30 930 4 491 1 48 1 16515 0 30 74 7 491 3 48 1 16965 0 08 225 8 503 5 48 1 17165 0 20 293 9 509 1 48 1 17715 0 04 484 6 525 1 48 1 17875 0 08 541 0 530 0 48 1 18646 0 02 819 9 554 5 47 1 20016 0 12 414 9 594 8 47 1 20076 0 20 435 4 596 8 Continued on next page 50 Order A um Intens X pix Y pix A7 1 20256 0 18 497 1 601 9 47 1 20316 0 24 517 8 603 7 A7 1 20559 0 07 602 4 611 2 A7 1 21226 0 54 840 1 632 7 47 1 21359 0 20 888 6 637 1 47 1 21550 0 05 958 8 643 7 J set 49 1 14364 0 40 160 9 160 2 49 1 15395 0 32 523 2 185 0 49 1 15665 0 02 621 2 192 0 49 1 15925 0 35 717 0 198 9 49 1 16285 0 12 851 9 208 8 48 1 16285 0 12 7 4 210 3 49 1 16515 0 30 939 7 2154 48 1 16515 0 30 83 5 215 4 48 1 16965 0 08 234 6 225 6 48 1 17165 0 20 302 8 230 3 48 1 17715 0 04 493 6 243 8 48 1 17875 0 08 550 1 247 9 48 1 18646 0 02 829 1 268 5 A7 1 20016 0 12 423 8 302 2 47 1 20076 0 20 4443 308 7 47 1 20256 0 18 506 1 308 2 47 1 20316 0 24 526 9 309 7 47 1 2
10. A short series of lamp ON and OFF frames are taken single images combined and the resulting median ON and OFF images subtracted to get the final one For certain settings the areas occupied by two consecutive echelle orders may overlap for the shortest wavelength This is however not an issue for point sources and extended sources that fit completely into the slit length As for the imaging dark current and bias frames are not in the standard routine The wavelength calibration is initially based on spectra of an Ar lamp taken at the be ginning or end of the night separately for each setting Usually no Ar exposures are taken during the observations as it is normally done in optical so they do not have to be included as overheads when observations are planned A short series of lamp ON and OFF frames are taken single images combined and the resulting median ON and OFF images subtracted to get the final one Atmospheric absorption features telluric bands or OH emission lines may serve for a further wavelength calibration Their positions together with sample images and echellograms can be found here http www naoj org staff pyo Echellogram Echellogram STD IRCS2 html html or http www naoj org bserving Instruments IRCS echelle pdf Echellogram STD IRCS pdf If the NH3 is used a precise wavelength solution in part of the K band can be obtained on the basis of the ammonia features 3
11. PA 66 6 e TTSLEEP and TTSTEP if MODE TTNULL currently not recommended Additionally for L and M band imaging add SetClock DEF IRST SLWCNT 1 before the SetupField command and SetClock DEF_IRST SLWCNT 16 after the GetObject command This will change the IRCS clock pattern to decrease the shortest integration time from 0 41 to 0 12 s and to thermal readout mode In such case NDUMMYREAD 0 is mandatory in the GetObject line In spectroscopic modes one can define the following parameters depending on the mode and observing sequence e MODE AOP recommended or MODE TTNULL for AO correction e Pixel scale only with AO PIXSCALE 52MAS or PIXSCALE 20MAS for grism or SV in echelle mode We do not recommend using no guiding for any spectroscopic mode 40 e For no AO observations SLIT PA 0 0 or any value that was given in the SetupField command Do not put SLIT_PA for observations with AO e For ABBA the nodding width distance between two positions on the slit with the parameter DITH like in imaging e For OSO and OSSO the angular offsets from the object to the sky position RA OFFSET and DEC_OFFSET both in arcsec Also define DITH if you wish to come to a different object position along the slit after the sky observation e For slit scanning an exact scanning pattern must be defined with the parameter SCAN PAT 1 2 3 gt Each lt pos_N gt is a set of three numbers meanin
12. Subaru Telescope instrument IRCS necessary to prepare and conduct successful observations and collect them in a single up to date handy document It is not however intended to explain the operations itself in details only what is required from the user s point of view This manuscript includes e Overall description of the IRCS and its components e Characteristics of the observing modes e Tools and templates useful for preparing the observations 1 2 Additional Information We tried to gather as much important information as possible but we might still be missing some If you can t find what you need please refer to the instrument website http www naoj org Observing Instruments IRCS index html and the links and references therein Some information may be slightly different we tried to put the most recent ones in here Two papers describing the IRCS are available e Tokunaga et al http www naoj org Observing Instruments IRCS spie1998 pdf 900 kB e Kobayashi et al http www naoj org Observing Instruments IRCS spie2000 ps gz 2 MB Questions regarding IRCS should be directed to Ji Hoon Kim jhkim at naoj org or Tae Soo Pyo pyo at naoj org Figure 1 1 Location of the IRCS blue box at the Nasmyth IR NsIR platform The black semi transparent box is AO188 The blue wall to the left separates the NsIR platform from the telescope 1 3 Abbreviations AO adaptive optics BLIP background limited p
13. This detector also suffers from non linearity Signal levels below 6000 ADU 22 800 e are recommended to achieve linearity better than 1 For this detector a bad pixel map is also available There are more bad pixels than for the imaging array and they are more concentrated thus it is highly recommended to use this map for the data reduction http www naoj org Observing Instruments IRCS echelle spg_badpix coo As in the camera section fast readout is accepted for echelle for bright targets for example Please remember that frequent changes of readout mode will result in detector problems and unnecessary delays 20 Table 3 7 Basic parameters of the IRCS echelle spectrograph camera Pixel scale 54 93x68 20 mas FOV 3 5 9 4 in slit length Gain 3 8 e ADU Dark current 0 05 e7 s Readout noise 68 e rms Saturation level 129 000 e Readout rate 0 41 s standard 0 12 s fast a per NDR readout noise per frame readout noise per NDR sqrt NDR b for the full 1K x 1K array size Table 3 8 Settings and sensitivities for the echelle spectroscopy with IRCS Band Coverage R A AA Dispersion Slit Standard sets to Sensitivity name um for 0 14 slit pix length cover the whole band mag as Iz 0 92 1 01 20 000 0 22 3 47 1 set Iz zJ 1 03 1 18 19 000 22 600 0 25 0 28 3 47 1 set zJ 15 27 J 1 18 1 38 19 000 22 600 0 28 0 33 3 47 1 set J 1
14. but in the first one in spectroscopic modes it only serves for taking an acquisition image in the K band so put DEF_IMK The complete list of possible values is very extensive They can all be found under this URL http www naoj org staff pyo IRCS Preparation OPE for IRCS html Mechanism Definition Additional parameter TMODE tracking mode should be indicated for AO observations TMODE SID for sidereal targets NON SID for non sidereal targets and ADI for angular differen tial imaging When a tip tilt guide star was defined for the LGS AO correction the command has to come with more parameters Examples SetupField DEF IMSTA DEF IM20H 37GEM TMODE ADI ADI H band imaging with AO in the 20 mas pixel scale SetupField DEF GRSTN DEF IMK 37GEM grism spectroscopy without guiding no AO SetupField DEF ECSTV DEF IMK 37GEM echelle spectroscopy with guiding no AO SetupField DEF IMSTA DEF IM20K TT STAR TMODE SID A0188 OFFSET RADEC DEF AOLN 37GEM K band imaging with LGS 20 mas pix scale where TT STAR is the alias of the ad ditional tip tilt star defined as a separate object earlier and 37GEM is the alias of the science target CheckField The CheckField command is for 1 changing mechanism to a proper setting used for the further scientific observations 2 taking a test frame with the given EXPTIME to check the field imaging or spectrum intensity level The first parameter is the same as in SetupFi
15. e 0000 ceat 0006 SAOLE 000 I 000 0800y 00006 0001 66707 NOSIAVANOD 1 dy IV TUD Jrquopr 1102 550 1 98 92 10 Dak eooppeeudsogoKd LYOdXAPVI ZA AVUL OVON 8 6 qysuo oAeM 0009 00GCY 0000F OOGLE 000G 00Sc 00006 UU G Z 000c 0008 60506 0006 06698 0006 0006 SOLE 0000 26796 00016610 0008 96462 0000 EESTE 0007 0009 0006 28482 NOSIUVd WOO 1 dy uaeopo ay T49 JIPUSPI 1102 550 1 98 92 10 P M e2oppeezdsgoKd LYOdXAVI GA AVAI OVON suons ue qysuo oAeM T CAE GE GG 92Uu9j3rusu ead NLY pueq T 1 dy NLVT 00211 Jruopr T02 29 E T PT PT ZZE ang teooppeegds goKd LHOdXAVI ZA AVUL OVON
16. have slit viewer The accuracy of slit position depends on the telescope tracking and the auto guider performance 3 2 2 Grisms and order sorting filters A single grism can be used to provide spectra in various bands like JH K so the wavelength range band is determined by selecting a combination of a grism with an order sorting filter OSF The IRCS currently has one grism that works in the 20 mas mode but two different spectral orders cover either the 127 or JHK bands and OSFs are used to set the band Four grisms work in the 52 mas mode and produce spectra of higher resolution Tables 3 4 and 3 5 summarize the wavelength range sensitivities and spectral resolutions for grisms OSF s for the 20 and 52 mas modes respectively 3 2 3 Sensitivity corrections All sensitivities in Tables 3 4 and 3 5 are limits for 5o detections per pixel in 1 hour of on source integration usually assumed to comprise six 600 second integrations using the 0 15 slit Because the spectrum is properly sampled with this slit spectra taken with wider slits can be binned in the dispersion direction to increase sensitivity by 1 25log N mag where N is the number of pixels being binned equal to 2 4 or 6 for the wider slits Further improvement in sensitivity for point sources can be done by extracting the spectrum along several spatial pixels Apertures between 1 and 2 times the seeing FWHM are optimum Corrections from Tab 3 6 be added to the numbers
17. in the above tables to determine the point 16 X 47 105 126 176 256 307 330 360 402 451 Refl 4 3rd slit Refl 4 4th slit 471 512 516 539 C X 593 976 E E rr 75 512 156 512 res TER 5 4 W 0 3 slit 01 282 512 345 510 27 510 5 w 5 slit W 0 1 slit 785 509 W 0 225 slit 0 528 510 574 510 11 29 05 Reflective 4 slit it e zi zs dite fee one a a e 0 dh Figure 3 6 Reflective slits of the IRCS Frop to bottom R3W at 52 mas R4 at 52 mas R3W at 20 mas R4 at 20 mas Some X Y pix coordinates are noted Note the defects on 0 9 R3W 0 15 and 0 3 R4 slits Also note the bad pixels in the center of the image Boxes mark parts of slits suggested for placing an object 17 Table 3 4 Parameters for grism spectroscopy with the 20 mas mode Coverage R A AA vs slit Sensitivity Band um 0 10 0 15 0 225 0 45 mag as Iz 0 92 1 01 813 542 361 181 16 4 zJ 1 03 1 18 745 497 331 166 16 4 J 1 19 1 38 677 452 301 151 16 4 H 1 47 1 80 501 334 223 111 15 3 K 1 92 2 40 393 262 175 87 14 9 Approx slit length 7 0 6 5 6 5 18 0 Table 3 5 Parameters for grism spectroscopy with the 52 mas mode Coverage R A AA vs slit Sensitivity Band um 0 10 0 15 0 225 0 30 0 45 0 60 0 9
18. read any part of the chip only squared boxes in the center The allowed sizes side of square in pix are 64 128 256 384 512 640 768 and 896 12 Table 3 2 Broad band filters of the IRCS camera section Sensitivity mag for Filter Center Width mag mag as 1e s name um um w AO w o AO w AO w o AO w AO w o AO 20 amp 52 mas 20 amp 52 mas 20 amp 52 mas 20 mas 52 mas 20 amp 52 mas 20 amp 52 mas Y 1 02 0 103 TBD TBD TBD TBD 25 8 TBD J 1 25 0 16 23 5 23 6 19 6 20 6 26 1 26 3 H 1 63 0 30 22 7 22 8 18 6 19 6 26 3 26 5 K 2 12 0 35 RI 22 6 18 4 19 4 25 8 K 2 20 0 34 22 2 22 3 18 2 19 2 25 5 25 7 Le 3 77 0 70 17 1 13 3 14 3 24 7 24 7 Mtb 4 68 0 24 14 6 10 8 mE 22 5 22 6 4 LU observation with the 52 mas pixel scale is limited to a maximum 512x512 27 x27 subarray with AO and 896x896 47 x47 subarray without AO gt M observation is limited to 20 mas pixel scale mode Imaging in L and M bands is very sensitive to weather and airmass hence there are limitations for the field of view In the L band the largest allowed FOV is 20 x20 so the largest sub array is 512x512 pix in the 52 mas scale In the M band the FOV should be adjusted to the conditions and the 512 in 52 mas or full size in 20 mas can not be guaranteed Please note that the fast thermal readout mode is suggested for E M but is also accepted for NIR bands for bright targe
19. 0 mag as Iz 0 92 1 01 1940 1249 862 647 431 323 216 17 3 zJ 1 03 1 18 1706 1137 758 569 379 284 190 17 3 J 1 18 1 38 1432 955 637 477 318 239 159 17 0 H 1 49 1 83 1146 764 509 382 255 191 127 16 1 K 1 93 2 48 869 579 386 290 193 145 97 15 6 L 2 84 4 16 331 220 147 110 73 55 37 10 8 23H 0 95 1 50 705 470 313 235 157 118 78 J 17 5 H 16 6 Ak 1 40 2 50 442 294 196 147 98 74 49 H 16 7 K 16 0 Approx slit length 7 0 7 0 20 14 18 15 15 source sensitivity in the relevant seeing conditions Note that the first two rows represent image quality only attainable with AO Please ensure you use the correct table for your choice of grism Increasing the slit width will improve the sensitivity of an extended source if its surface brightness remains constant Corrections to be applied to the numbers from Tables 3 4 and 3 5 are the following 0 97 mag for 0 90 slit 0 75 for 0 60 0 38 for 0 30 and 0 0 for 0 15 Again sensitivity can be improved by binning in the spatial direction 1 25 log N mag for binning over N pixels If the source is too extended to be nodded along the 20 long slit remember to double your integration time to allow for observations of blank sky 3 2 4 Grism spectroscopy calibrations Calibrations for the grism spectroscopy include flat field and Ar lamp images As for the imaging flats are taken using a continuum source halogen lamp exposures at the beginning or end of the night
20. 0 28 1 97029 0 35 87 1 218 5 28 1 97362 0 05 149 5 223 0 28 1 97515 0 20 178 3 225 1 28 1 97718 0 52 216 7 228 0 28 1 98397 0 22 346 5 237 6 28 2 00082 1 05 678 7 263 3 28 2 00332 0 35 729 3 267 3 27 2 04127 1 28 51 3 326 8 27 2 04993 0 27 208 0 338 6 27 2 05636 1 05 326 3 347 7 27 2 06729 0 03 531 7 363 9 27 2 07290 0 77 639 4 372 6 27 2 08603 0 20 898 3 394 0 27 2 09096 0 33 998 1 402 5 26 2 11766 0 38 14 7 443 1 26 2 12325 0 15 111 4 450 6 Continued on next page 56 Order A um Intens X pix Y pix 26 2 12497 0 41 141 3 452 9 26 2 12791 0 05 192 8 457 0 26 2 13180 0 01 261 4 462 4 26 2 13260 0 16 275 6 463 6 26 2 15050 0 01 599 9 490 1 26 2 15073 1 20 604 2 490 5 26 2 15121 0 01 613 1 491 2 26 2 15376 0 30 660 6 495 2 26 2 15807 0 15 741 6 502 1 26 2 17111 0 25 992 7 524 0 25 2 21255 0 80 184 7 585 3 25 2 22479 0 28 393 9 602 7 25 2 23127 0 50 507 0 612 3 25 2 24603 0 10 771 4 635 4 25 2 25180 0 25 877 6 645 0 K set 29 1 95181 0 15 241 2 114 9 29 1 95611 0 12 332 3 121 0 29 1 95932 0 05 401 1 125 7 29 1 96425 0 30 508 1 133 0 29 1 96990 0 15 632 9 141 8 29 1 97029 0 35 641 6 142 4 29 1 97362 0 05 716 4 147 7 29 1 97515 0 20 751 1 150 2 29 1 97718 0 52 797 4 153 6 29 1 98397 0 22 954 8 165 2 28 2 01933 0 15 196 9 217 9 28 2 02759 1 00 365 7 220 0 28 2 03395 0 55 498 6 239 0 28 2 04127 1 28 654 8 250 4 28 2 04993 0 27 844 8 264 6 28 2 05636 1 05 989 7 275 6 27 2 08603 0 20 40 9 320 6 27 2 09096 0 33 135
21. 0006 CAD NOAO IRAF V2 14 1 pyo0DGCVCCC1 Thu 14 02 1 2555 1 00E5 75000 90000 25000 25000 12500 10000 Smorjsdue 019 UI IAR Y 00095 000rvc 000cc 0000c 0008I 0009I 00066 00066 0001 BEETS 0008 16607 0001791006 wew 0006 SETE 0002 68022 c 000922602 0000 c em ma 000 BE9 0006 ELLE 000961621 00064 0009 06051 S300 T CdCe T GHOST 0702 6169 XH NSIAD TT IV MHYUDS Ajr3uopr IT08 09 10 29 92 00 NUL 15591 peeads gokd LHOdXAVI ZA AVUL OVON suod3s9ue YY USTIAL Y 00911 00011 00901 00001 0096 0006 0098 6504 9666 C400 c6 gt c gt 60601468 CHO0 Y 00670996 GH00 9 ZI 151315 TT JAY USTAD 2 5 JI UOPpI TTOG 990 ET 68 08 20 eooppeezdgdsooKd LHOdXAVI ZA AVAI OVON 8 6 qysuo oAeM 000 I 009621 00061 00911 00011 00901 00001 0000 SPP TT 00089661 0006 1901 001 6660 9006 6990 C400 6 0006 TAITI e eo Do gt 0005 94901 cH400 y G400 9 Z WSIY9 TT IVO wstay fZ JI UOPI 1102 550 81 81 89 90 eooppeezdgdsooKd LHOdXAVI ZA AVAI OVON suod3s9ue YY USTIAL M 00091 00 UT L 00061 000521 0109 01141 0006 0146 0000 0001 6027 is gt co gt
22. 0559 0 07 611 4 316 0 A7 1 21226 0 54 849 3 334 0 47 1 21359 0 20 897 8 337 8 46 1 21359 0 20 13 1 338 9 47 1 21550 0 05 968 1 3432 46 1 21550 0 05 73 7 343 1 46 1 21964 0 11 206 6 352 5 46 1 22293 0 40 313 9 360 2 46 1 22578 0 18 408 2 367 1 46 1 22870 0 46 506 0 374 3 46 1 23259 0 17 638 6 384 3 46 1 23516 0 30 727 7 391 2 46 1 24009 0 11 902 0 404 8 46 1 24230 0 19 981 8 411 2 45 1 24230 0 19 67 1 411 0 45 1 24827 0 04 259 1 424 6 45 1 25024 0 09 318 2 429 2 45 1 25891 0 05 602 7 450 8 A4 1 27528 0 15 212 9 493 0 A4 1 27644 0 21 248 9 495 8 A4 1 27825 0 24 305 5 500 0 44 1 28070 0 23 3828 505 9 44 1 28346 0 08 470 9 512 7 44 1 29057 0 57 703 2 531 1 Continued on next page 51 Order A um Intens X pix Y pix 44 1 29212 0 17 755 0 535 2 44 1 29431 0 09 828 8 541 3 44 1 29857 0 15 9749 553 4 43 1 29857 0 15 223 553 7 43 1 30216 0 32 129 2 561 6 43 1 30528 0 21 223 2 568 7 43 1 30852 0 39 322 2 576 4 43 1 31278 0 18 454 3 586 7 43 1 31567 0 19 545 5 594 0 43 1 32110 0 10 720 0 608 2 43 1 32366 0 27 804 615 1 43 1 33019 0 01 10233 633 7 42 1 33019 0 01 42 6 633 3 42 1 33247 0 04 108 9 638 3 42 1 34208 0 06 394 8 660 7 41 1 36749 0 01 181 1 726 0 41 1 36772 0 01 187 7 726 5 41 1 36921 0 01 230 7 729 9 41 1 37168 0 01 302 6 735 7 41 1 38237 0 01 622 2 762 3 H set 38 1 46651 0 14 115 9 175 0 38 1 46984 0 35 203 3 181 0 38 1 47022 0 01 213 3 181 8 38 1 47133 0 01 242 7 183 9 38 1 47400 0 10 313 8 188 9 38 1
23. 14 2 154 162 170 181 1300 K 111 128 13 6 148 15 6 16 3 174 2800 K 11 0 12 7 13 5 147 15 5 16 2 17 3 2100 Saturation magnitudes and maximum exposure times Table 4 2 shows magnitudes of faintest objects that saturate in a given filter after a single integration of a given exposure time Maximum exposure times are also given Please remem ber that significant non linearity appears for signals higher than 4000 ADU in JH K and 7000 ADU in LM bands Due to high thermal background in LM bands only the maximum integration time can be given In the L band they are 0 20 and 0 62 s for the 52 and 20 mas modes respectively In the M band it is 0 28 s for the 20 mas mode 52 mas mode is not allowed for M Imaging exposure time calculator ETC There is one common ETC tool for several imaging instruments available at Subaru including the IRCS in both 52 and 20 mas modes http www naoj org cgi bin img etc cgi Chose the instrument IRCS 52mas or IRCS 20mas the kind of source point or extended and number of days from new moon to simulate the background level Set the appropriate band and brightness of the object in proper units Vega mag AB mag or uJy Set the seeing and size of the aperture in which the total flux will be calculated It is assumed to be circular for point sources and square for extended To mimic the AO188 correction set the seeing to 0 1 and aperture to 0 2 0 3 In Require at least exposures you c
24. 3 2 3 7 0 4 1 8 2 8 3 5 0 5 1 5 2 5 3 3 0 7 0 9 2 0 2 8 1 0 0 4 1 4 2 4 LM 0 00 0 38 0 75 Additional correction for L and M bands 50 54 slit available but not default 3 3 3 Sensitivity corrections All sensitivities in Table 3 8 are 50 detections per pixel for a single exposure of 3600 s using the 0 14 slit Because the spectrum is properly sampled with the 0 14 slit spectra taken with wider slits can be binned in the dispersion direction to increase sensitivity by 1 25 log N mag where N is the number of pixels being binned equal to 2 or 4 for the wider slits If more than one exposure is taken the signal to noise ratio will decrease by the square root of the number of exposures Further improvement in sensitivity for point sources can be done by extracting the spectrum along several spatial pixels Apertures between 1 and 2 times the seeing FWHM are optimum Corrections from Table 3 12 should be added to the numbers from Tab 3 8 to determine the point source sensitivity in the relevant seeing conditions There are additional corrections to be made for thermal IR bands LM observations do not neglect them Increasing the slit width will improve the sensitivity of an extended source if its surface brightness remains constant Corrections to be applied to the numbers from Table 3 12 are the following e zJ H K band 0 0 mag for 0 14 slit 0 75 for 0 27 1 51 for 0 54 e LM ban
25. 3 7 Echelle data reduction A document presenting a typical procedure to reduce and analyze the IRCS echelle spectra has been prepared http www naoj org staff pyo IRCS reduction pdf http www naoj org staff pyo IRCS and Reduction IRCS reduction html html Note that this document is partially based on data from 2003 and different configuration is now used The overall reduction procedure remains the same 24 Table 3 13 Basic information about the polarization modes Modes Imaging polarimetry Spectropolarimetry Wavelength 0 95 2 5 um Pixel scale 20 mas 52 mas 52 mas only 0 60 x 4 4 FOV of 20 mas 4 4 x21 x2 area 0 15 x 4 4 mask slit 52 mas 4 4 x54 x4 area 0 10 x 4 4 0 225 x 4 4 Retarder Quartz MgF half wave plate 0 7 2 5um Polarizer LiNbO3 Wollaston prism o e oe o e 0 e o e 6 o 6 0 e 1024 pixel 54 Dispersion axis 1 45 2 55um lt gt 4 4 4 4 Figure 3 8 Sample imaging polarimetry left and spectropolarimetry frames both taken in 52 mas pixel scale Target is located in the second mask slit 3 4 Polarimetry shared risk This mode has been introduced recently The presented information are mostly preliminary and may be changed or updated in the future The IRCS provides several linear polarimetry modes in 0 95 2 5 um from S15B as Shared Risk mode Imaging polarimetry is available for Y J H and K K bands Spectropo larimetr
26. 365 1 472 1 509 0 357 Table 3 10 Wavelength coverage for sets covering band K Set K Set K Set K Ord Wavelength Disp Wavelength Disp Wavelength Disp no um A pix pom A pix um A pix 23 2 402 2 466 0 619 2 446 2 504 0 569 2 393 2 455 0 602 24 2 302 2 363 0 592 2 344 2 400 0 547 2 293 2 353 0 581 25 2 210 2 268 0 568 2 250 2 304 0 527 2 201 2 259 0 562 26 2 125 2 181 0 546 2 163 2 215 0 508 2 116 2 172 0 543 27 2 046 2 099 0 525 2 083 2 134 0 491 2 038 2 092 0 525 28 1 973 2 024 0 506 2 009 2 057 0 475 1 965 2 017 0 508 29 1 904 1 954 0 488 1 940 1 987 0 460 1 897 1 948 0 492 Table 3 11 Wavelength coverage for sets covering band L Set A B Set 0 80 Set A B Ord Wavelength Disp Wavelength Disp Wavelength Disp no um A pix um A pix um A pix 14 3 881 3 989 1 058 3 984 4 084 0 981 4 068 4 161 0 910 15 3 622 3 723 0 987 3 718 3 812 0 914 3 797 3 884 0 850 16 3 396 3 490 0 926 3 486 3 574 0 858 3 560 3 641 0 797 17 3 196 3 285 0 872 3 281 3 364 0 809 3 350 3 427 0 750 18 3 018 3 103 0 823 3 099 3 177 0 763 3 164 3 237 0 708 19 2 859 2 939 0 780 2 936 3 010 0 722 2 998 3 066 0 670 Sets A include orders 15 19 while sets B orders 14 17 only 22 Table 3 12 Corrections to the point source sensitivities as a function of slit width and seeing Correction mag Seeing 0 14 slit 0 27 slit 0 54 slit 0 3 2 2
27. 47837 0 15 164 3 185 0 38 1 47998 0 30 207 6 187 9 38 1 48057 0 26 223 5 189 0 38 1 48330 0 62 297 6 194 1 38 1 48644 0 20 383 8 200 2 38 1 48862 0 01 444 3 204 5 38 1 48877 0 78 448 5 204 8 38 1 49091 0 10 508 4 209 1 38 1 49319 0 26 572 8 213 7 38 1 50067 0 01 788 6 229 7 38 1 50261 0 01 845 8 234 0 38 1 50528 0 01 925 4 240 1 38 1 50555 1 95 933 5 240 7 38 1 50640 0 01 959 1 242 7 38 1 50689 0 66 973 9 243 8 37 1 51870 0 38 174 1 266 7 37 1 52410 1 41 316 6 276 8 37 1 52878 0 58 442 3 285 9 37 1 53324 1 15 564 4 294 9 Continued on next page 54 Order A um Intens X pix Y pix 37 1 53953 0 40 740 3 308 2 37 1 54321 1 08 845 5 316 3 37 1 54621 0 10 932 6 323 1 37 1 54744 0 01 968 7 325 9 36 1 55404 0 55 19 3399 36 1 55462 0 01 16 3 340 9 36 1 55702 0 15 76 4 345 1 36 1 55977 0 70 145 7 350 1 36 1 56313 0 01 231 3 356 2 36 1 56316 0 35 232 1 356 3 36 1 56550 1 05 292 3 360 7 36 1 56570 0 01 297 5 361 1 36 1 57025 0 28 416 1 369 8 36 1 57603 0 10 569 7 381 5 36 1 57821 0 15 628 6 386 0 36 1 58303 0 01 760 6 396 3 36 1 58332 2 30 768 6 396 9 36 1 58481 0 90 810 1 400 2 36 1 58693 0 25 869 5 404 9 36 1 58973 0 10 9488 411 3 36 1 59159 0 01 1002 1 415 7 35 1 60308 1 53 1149 437 9 35 1 60798 0 65 236 1 446 9 35 1 61286 1 71 358 7 456 1 35 1 61947 0 63 528 3 469 2 35 1 62354 1 27 634 9 477 6 35 1 63172 0 28 854 4 495 3 35 1 63418 0 12 922 0 500 9 35 1 63513 0 65 948 2 503 1 35 1 63604 0 10 973 5 505 2 34 1
28. 5 09 H 1 49 1 83 18 800 22900 0 36 0 44 5 17 2 set H H 14 60 K 1 90 2 49 18 300 22300 0 46 0 62 5 17 2 set K K 14 11 2 80 4 20 17300 25100 0 67 1 06 6 69 6 set LA LAO LA LB LBO LB 10 59 4 41 5 34 16800 26300 1 16 1 30 6 69 4 set M M M M 9 04 a Offered in shared risk mode The 0 27 slit for L and M bands is 9 37 long The 0 54 slit is available but not by default 3 3 2 Echelle configurations The highest resolution is achievable only with a narrow 0 14 slit and it is highly recommended to use the AO188 with it The length of the slit is dependent on the band shorter slits are used in shorter wavelengths This is determined by the separation of echelle orders which is smaller for shorter wavelengths Please note that the longer the wavelengths the less orders can be recorded on a single frame For this reason if you wish to cover the whole band from H onwards you need to make two or more observations in various settings Table 3 8 summarizes the basic spectrograph parameters for each band and lists the sets that are needed to cover them whole Note that the resolutions are given for the narrow 0 14 slit To calculate the resulting resolution obtained with wider slits divide the values from the Table 3 8 by 2 for the 0 27 and by 4 for the 0 54 slit not available by default for L and M Tables 3 9 to 3 11 show the wavelength coverag
29. 63604 0 10 46 1 518 9 34 1 63885 0 25 111 4 523 9 34 1 64147 0 20 172 8 528 7 34 1 64421 0 01 237 5 533 7 34 1 64476 0 70 250 6 534 8 34 1 64764 0 01 319 3 540 2 34 1 64790 0 50 325 5 540 7 34 1 65023 0 75 381 6 545 2 34 1 65539 0 30 507 5 555 4 34 1 65863 0 01 587 6 562 0 34 1 66110 0 10 649 4 567 1 34 1 66892 0 01 848 7 5841 34 1 66921 2 30 856 2 584 7 34 1 67088 0 83 899 7 588 5 34 1 67325 0 30 961 8 593 9 33 1 68405 0 30 11 0 616 3 33 1 69037 1 45 153 6 627 5 33 1 69551 0 52 271 5 637 0 33 1 70088 1 80 396 8 647 3 33 1 70783 0 70 562 6 661 2 33 1 71236 1 20 671 9 670 6 Continued on next page 53 Order A um Intens X pix Y pix 33 1 72104 0 36 887 7 689 6 33 1 72486 0 70 985 0 698 3 32 1 73838 0 40 48 0 725 5 32 1 73867 0 40 543 726 0 32 1 74270 0 30 142 7 733 2 32 1 74499 0 72 1934 737 3 32 1 75013 0 27 308 3 746 9 32 1 75060 0 08 318 9 747 8 32 1 75294 0 08 371 9 752 3 32 1 76532 2 00 658 9 7773 32 1 76718 0 70 703 0 781 2 32 1 76984 0 18 766 7 787 0 31 1 79348 0 05 27 4 836 8 31 1 79940 1 42 153 1 847 4 31 1 80679 0 18 312 8 861 1 31 1 81185 0 50 424 1 870 8 31 1 82110 0 01 632 2 889 6 31 1 82542 0 05 731 6 898 7 31 1 83528 0 01 964 3 920 6 31 1 83646 0 01 992 7 923 4 31 1 84004 0 01 800 8 915 0 31 1 84017 0 01 803 9 915 2 31 1 84023 0 01 805 4 915 4 31 1 84335 0 01 880 7 922 3 31 1 84595 0 01 944 2 928 2 H set 38 1 47400 0 10 48 0 177 1 38 1 47556 0 05 89 3 179 9 38 1 47724 0 15 134 1 182 9 38 1
30. 9 99 99 99 99 99 99 99 CLOSE UNKNOWN UNKNOWN UNKNOWN UNKNOWN UNKNOWN LTCS LLT LLT LLT LLT LLT M d v3 ay A Generation status EMIT SHUTTERED OFF Output power of SFG589 W Status of power control unit Status of remote control unit Brightness of Sodium gas cell Gain of PMT for Sodium gas cell Temperature of Sodium gas cell ID of Laser Fiber Power returned from LLT through fiber Gain range of returned power LaserRoom LLT Laser Collimator Collimator Collimator Overall throughput of relay fiber Overall status launching status ON OFF lens lens lens X stage pos micron Y stage pos micron Z stage pos micron M3X Stage position of micron 3000 LLT M3Z Stage position of micron Laser power Temperature Temperature Temperature Temperature LLT Shutter status OPEN CLOSE Policy FirstON Classical Status of shuttering OPEN CLOSE Laser propagation status ONSKY ON OFF Status of collision with telescopes Status of collision with satellite LTCS LTCS LTCS LTCS at at at at at LLT Watt OPT side degC IR side degC FRONT side degC REAR side degC 999999 LTCS Time until telescope collision sec 999999 LTCS Time until satellite collision sec OPEN 1 Camera Wheel 1 element name 1 Camera Wheel 1 puka 3046 Camera Wheel 1 Hall Value 3050 Camera Wheel 1 motor position CK Camera Wheel 2
31. Object DEF_GRSSV SCAN PAT 0 25 120 1 0 1 120 1 0 1 120 1 0 1 120 1 0 1 120 1 0 1 120 1 grism spectroscopy with guiding but no AO correction slit scanning on six positions 0 1 apart single 120 second exposures on each position 41 Chapter 5 Appendix 5 1 Fits header This is an example of a header of an output IRCS fits file This particular observation was an echelle spectrum in the J band four coadds 15 s each AO188 NGS first position of the ABBA sequence Al Note such keywords as DATA TYP OBS MODE EXP1TIME EXPTIME COADD DET ID FILTERO1 DISPRSR D MODE I DTHPAT and I_DTHPOS SIMPLE T Fits standard BITPIX 32 Bits per pixel NAXIS 2 Number of axes NAXIS1 1024 Axis length NAXIS2 1024 Axis length EXTEND F File may contain extensions ORIGIN NOAO IRAF FITS Image Kernel July 2003 FITS file originator DATE 2014 12 31T21 47 41 Date FITS file was generated IRAF TLM 2014 12 31T22 15 52 Time of last modification I FNAME IRCA00397373 7 FRAMEID IRCAO0397373 7 EXP ID IRCA00397373 7 1 HDRVER 3 10 IRCS HEADER VERSION OBSERVER Helminiak Observer INSTRUME IRCS Instrument TELESCOP SUBARU Telescope OBS ALOC Observation Observation or Standby OBSERVAT NAOJ Observatory OBJECT GJ 406 Object DATA TYP OBJECT Data Type OBS MOD ECHELLE Observation Mode DETECTOR Aladdin3 SCA 420055 Name of detecto
32. R pupil position angle deg D_IMRRA 10 56 28 865 IMR tracking right ascension 12000 44 D_IMRDEC D_SADC D_SADCP D_SADCST D_SADCMD D_SADCA1 D_SADCA2 D_SADCFC D_SADCRA D_SADCDC D_SADCPA D_TTX D_TTY D_WTTC1 D_WTTC2 851 7 851 852 7 852 D_FCONV D_FCONVP D_AU1X D_AU1Y D_AU1XA D_AU1YA D AU1FOC AU1TX D_AU1TY D_AU1M1X D_AU1M1Y D_AU1M1Z D_AU1M2X D_AU1M2Y D_AU1GSX D_AU1GSY D_AU2X D_AU2Y D_AU2XA D_AU2YA D_AU2F0C D_AU2TX D_AU2TY D_AU2M1X D_AU2M1Y 07 00 52 770 IMR tracking declination J2000 OUT SciPath ADC position IN OUT O SciPath ADC position mm ASYNC SciPath ADC tracking status ADT SciPath ADC tracking mode O SciPath ADC prism 1 position deg O SciPath ADC prism 2 position deg 1 SciPath ADC prism angle correction factor 23 07 28 2 SciPath ADC tracking right ascension 72000 21 07 58 SciPath ADC tracking declination J2000 39 SciPath ADC tracking position angle deg 0 404 TT mount tip voltage V 0 41 TT mount tilt voltage V 5 447 HOWFS TT chi voltage V 5 004 HOWFS TT ch2 voltage V NIR1 BS1 position NIR1 NIR2 0PT 2 31 BS1 position mm MIRROR BS2 position BS589 MIRROR 152 63 BS2 position mm OUT 7 F conversion optics position IN OUT 75 F conversion optics stage position mm 0 65149 AU1 offset X mm 0 20105 AU1 offset Y m
33. RUMENT_DELTAZ 0 06 Focusing IRCS FocusOBE DEF_IRST DEF_IMK EXPTIME 1 COADDS 3 Z TSCL Z DELTAZ 0 07 Then for each observation a series of three commands follows They are SetupField DEF Mode lt DEF Mechanism 0bject name gt CheckField DEF Mode DEF Mechanism lt EXPTIME sec gt GetObect DEF Obsmode EXPTIME sec lt DITH arcsec gt COADDS n lt NDUMMYREAD n gt FIELD PA or SLIT PA deg gt other parameters depending on the observation mode The block ends with the following sequence Shutdown ShutdownQDAS DEF_IRST ShutdownVGW DEF_CMNT ShutdownOBE DEF_IRST lt Command gt SetupField The SetupField command is for 1 moving the telescope to the object named Object_name for example 37GEM 2 moving the field rotator to the value defined in the object list as FIELD_PA or SLIT_PA 3 moving the IRCS mechanisms like filter wheels slit wheel pixel scale to take an acquisition slit view image 4 in spectroscopy taking pictures to put the star on the slit 5 starting auto guiding if desired The last step is determined by the first parameter DEF Mode which has one of the values given in Table 4 4 It depends on the observing mode you choose Remember it must be preceded by the dollar sign The mechanism definition parameter DEF Mechanism controls settings of multiple elements 38 of the IRCS It is used in both SetupField and CheckField commands
34. S TT offload gain D PSUBG 0 01 RTS piston subtract gain D_DMCMTX ao188cmtx oct RTS DM control matrix D TTCMTX aoi88ttctrl oct RTS TT control matrix DWTTG 0 RTS HOWFS TT gain DLTTG 0 RTS low order TT gain D_LDFG 0 RTS low order defocus gain 8116 1 RTS high order TT gain D HDFG 1 RTS high order defocus gain D_ADFG O RTS AU1 defocus gain 5116 0 RTS secondary TT gain D_APDTI 99 9 APD coolant inlet temperature degC D APDTO 99 9 APD coolant outlet temperature degC D_BNCTI 15 3 Temperature of AO bench inside degC D_BNCTO 10 Temperature of AO bench outside degC 47 D_BNCHI D_BNCHO D_LSTATE D_L589P D_LPCUST D_LRCUST D_LDSC D_LDSCPG D_LDSCT D_LFID D_LFRP D_LFRPR D_LFTHP D_LRSTAT D_LTLNCH D_LTCLXP D_LTCLYP D_LTCLZP D_LTM3XP D_LTM3ZP D_LTLPWR D_LTTOPT D_LTTIR D_LTTFRT D_LTTRER D_LTSHUT D_LTCPOL D_LTCSHS D_LTCLST D_LTCTCS D_LTCSTS D_LTCTTW D_LTCSTW I_MCW1NM I_MCW1PK I_CW1HV I_CW1MP I MCW2NM I CW2PK I CW2HV I_CW2MP I MCW3NM 6 Humidity of AO bench inside 4 5 Hhumidity of AO bench outside UNKNOWN Laser 99 99 Laser UNKNOWN Laser UNKNOWN Laser 9 999 Diag 9 999 Diag 99 9 Diag 99999 Fiber 9 99 Fiber 99 Fiber 9 99 Fiber gt UNKNOWN gt UNKNOWN A t 25920 LLT 14648 LLT 12092 LLT 15000 LLT 99 99 9
35. Subaru Telescope Infrared Camera and Spectrograph IRCS User Manual Ver 1 0 1 K G Hetminiak T S Pyo J H Kim M Morris National Astronomical Observatory of Japan May 2015 Change record e 1 0 0 March 15 first version prepared mainly for proposal preparation KGH e 1 0 1 June 15 Added OPE files Appendix and info on output data Figures 1 1 and 3 1 changed Grism slit lengths added Authors added Other major and minor comments from TSP JHK and MM addressed Corrected language JB and some typos KGH Contents 1 Introduction 6 TIT Scope aan a ae las a A et Ae ted 6 1 2 Additional Information 6 1 3 Abbreviations xke Re ROUES XR VERE E eee Bas 7 2 General information 8 2 1 Overall Description y air ge uk ded OS ares ndo A a RERUM 8 22 AO188 adaptive optics system 8 2 3 Output files and data access 9 3 Observing modes 10 SL AMA AA AAA A AA AAA eee d 10 JL Detector sc ad amp ete Be a Ge A iS Sa 11 A e A ee Be a Ee hit ST Eus nu m his 13 3 13 Coronagraphy a sii asep i Aa ea A ee ee 13 3 1 4 Image anomalies 15 3 1 5 Imaging calibrations 15 3 1 6 Imaging data reduction 15 32 Grism spectroscopy ol 65 pisa A a RR RR UR 16 3 2 1 Reflectiveslits ieu ne
36. WAP1P O HOWFS ADC stage position mm ASYNC HOWFS ADC tracking status NORMAL HOWFS ADC tracking mode O HOWFS ADC prism 1 position deg O HOWFS ADC prism 1 position deg 1 HOWFS ADC prism angle correction factor 05 01 06 3 HOWFS ADC tracking right ascension 12000 45 16 30 HOWFS ADC tracking declination 12000 50 HOWFS ADC tracking position angle deg NONE HOWFS acq cam BS position 30 78 HOWFS acq cam BS position mm NONE HOWFS acq cam filter wheel 1 state O HOWFS acq cam filter wheel 1 pos deg NONE HOWFS acq cam filter wheel 2 state O HOWFS acq cam filter wheel 2 pos deg NONE HOWFS hires cam BS position 30 29 HOWFS hires cam BS position mm FULL HOWFS VM aperture 4 6466 HOWFS VM aperture size arcsec NONE HOWFS pupil cam BS position O HOWFS pupil cam BS position mm NOBS HOWFS LA focus stage position 19 1 HOWFS LA focus stage pos mm ND30 HOWFS LA filter wheel position 288 HOWFS LA filter wheel pos deg OPEN HOWFS LA shutter state OPEN CLOSE 24 52 HOWFS APD Average Counts kcps elem AASEC LOWFS AP1 name 17 93 HOWFS AP1 postition LWAD OUT LOWFS ADC stage position IN OUT D_LWADP D_LWADST D_LWADMD D_LWADA1 O LOWFS ADC stage position mm ASYNC LOWFS ADC tracking status NORMAL LOWFS ADC tracking mode O LOWFS ADC prism 1 position deg
37. a natural guide star is required The guide star should be brighter than R 16 5 mag located within 30 of the science target Please note that the image quality degrades rapidly with the distance The science target may be used as NGS For the LGS mode operations a natural tip tilt guide star TTGS is still required to correct for the tip tilt motion that cannot be sensed by the LGS Point sources brighter than R 18 mag located less than 60 from the target are recommended however in some circumstances extended or non sidereal objects are allowed The science target itself can be used as the TTGS For both LGS and NGS modes we recommend you to observe at elevations gt 45 The distortion maps for IRCS AO188 combination together with the IRAF script for correction are available from this URL http www naoj org Observing Instruments IRCS camera IRCS A0188_distortion 2 3 Output files and data access The raw output files are 1024x1024 pix or sub array size fits files which name starts with IRCA One file is made at one telescope position which means that for an observation in 5 point dither mode see Fig 4 1 you will get 5 output files no matter how many coaadds are defined See Section 5 1 in the Appendix for a sample IRCS fits file header The data can be obtained at the summit just after the observations You can also ask for data delivery Please fill in the Observation Data Request Form and submit it to the Operat
38. an also set how many exposures you want to have see Section 4 2 To calculate the exposure time you need to get the desired signal to noise ratio S N set the S N and click Calculate exposure time The ETC will then return the information about the required exposure and total time which includes readouts together with supplementary information about the background level flux within the selected aperture non linearity and saturation If you have chosen to make more then one exposure the integration time and S N information will also be given per exposure Limited to 512x512 pix sub array 29 To calculate the S N resulting from a given integration time set the time and click Cal culate S N ratio The ETC will then return the value of the final S N supplemented with information about the background flux non linearity and saturation Note that there are limitations on the shortest exposure time see Table 4 3 If more than one exposure is se lected the ETC will split the given time to the requested number of exposures and will also give S N per single frame Note that due to readout noise with the same total integration time multiple exposures will give a lower S N than a single one however you may end up in non linear regime or a saturation may happen In such case the ETC will suggest the number of exposures 4 1 2 Grism spectroscopy The SPectrocopic Integration Calculator Applet SPICA is a tool that shou
39. d http www naoj org bserving DataReduction Cookbooks IRCSsp cookbook 2010jan05 pdf 19 IR ARRAYS ECHELLE FOLD MIRROR FOUR MIRROR FILTER WHEEL y KA ANAST I GMAT SLIT WHEEL s y COL L IMATOR ei PLATE a o cross 7 a ES SPECTROGRAPH DISPERSOR OPTICAL TABLE Figure 3 7 Layout of the echelle spectrograph section of the IRCS 3 3 Echelle spectroscopy The second major section of the IRCS is the echelle spectrograph The light passes to it through one of the slits in the slit wheel that are cut in flat mirrors and what is reflected goes to the camera section which serves as a slit viewer in this configuration The layout is presented in Figure 3 7 The pixel scale is 55 mas along the pixel scale and slit widths of 0 14 0 27 and 0 56 are available The echelle offers spectral resolution R 20 000 0 14 slit and observations from Iz to M bands 0 9 5 34 um Unlike grism spectroscopy observations at JH K with the echelle are detector limited between OH lines Sky subtraction is therefore not an issue and long exposures can be made with the target at a single slit position 3 3 1 Detector The ALADDIN III detector of the echelle section is the same 1024x1024x27 m InSb array as in the camera section It however operates in a slightly different pixel scale lower gain and the read out parameters are a bit different The basic information is summarized in Table 3 7
40. d 0 0 mag for 0 14 slit 0 38 for 0 27 0 75 for 0 54 Again sensitivity can be improved by binning in the spatial direction 1 25log N mag for binning over N pixels 3 3 4 Single order filters IRCS offers three narrow band filters that leave only one specific echelle order allowing for observations focused around following lines e He 1085 nm 20nm band 1 073 1 093 um e Fell 1252 nm 25nm band 1 239 1 265 um e Fell 1650 nm 60nm band 1 616 1 676 um 23 3 3 5 Ammonia NH cell A NH gas absorption cell that enables the measurement a high precision radial velocities at the 30 m s level even with the spectral resolving power of IRCS R 20 000 The NH gas cell can be used in a part of K band with IRCS AO188 mode only Keep in mind that the absorption cell lowers the efficiency but the drop has not been precisely determined yet and it doesn t seem to be significant If you have any questions please contact Ji Hoon Kim jhkim at naoj org or Tae Soo Pyo pyo at naoj org The IR gas cell was provided by Andreas Seifahrt University of Chicago in collaboration with colleagues at the university of Goettingen Germany and Lund Observatory Sweden 3 3 6 Echelle calibrations Calibrations for the echelle observations include flat field and Ar lamp images As for the imaging flats are taken using a continuum source halogen lamp exposures at the beginning or end of the night separately for each setting
41. dep U rer buy Ruins 16 3 2 2 Grisms and order sorting filters 16 3 2 8 Sensitivity corrections 16 3 2 4 Grism spectroscopy calibrations oa 18 3 2 5 Grism data reduction eg i N Xow p D eise pO WS 19 3 3 Echelle spectroscopy Ress 20 3 9 doors ue kun rot eri du ue we TS aia ae es 20 3 3 2 Echelle configurations 21 3 3 3 Sensitivity corrections 23 3 3 4 Singleorderfillers 23 3 3 5 Ammonia NH3 cell 24 3 3 6 Echelle calibrations 24 3 3 7 Echelle data reductions ss vp eub a Ye 24 2 4 Polarimetry shared risk disce aa exo eoe Te E relies 25 3 41 Polarization efficiency 26 3 4 2 Instrumental polarization 26 3 4 3 Unpolarized and standard stars 26 4 Preparing and executing observations 28 4 1 Exposure times and their calculators 28 A Imagino juo teu IA A neum A R M 28 4 1 2 Grism spectroscopy 30 4 1 3 Echelle spectroscopy ara Le sis NE bee on eS ye mU M 30 4 2 Goadds and data cubes ama sti RR a ees 31 4 3 Dithering nodding object sky object and slit scanning 32 4 3 1 Dithering in the imaging mode
42. ds Please also see information about the sensitivities in each mode and detector performance 4 1 1 Imaging Background limited operation In order to achieve the maximum sensitivity in a given integration time individual exposures should be long enough for the photon shot noise from the sky background to dominate over the array read noise In practice background limited performance BLIP is considered to be when the sky counts exceed the square of the read noise by a factor of 3 Observations at U and M thermal IR are background limited even in the shortest exposure time Table 4 1 summarizes the information about background level and minimum BLIP time for each band The use of the infrared secondary mirror is assumed Table 4 1 Background level and minimum time for background limited performance Background min BLIP time s Filter mag asec e7 s asec 20 mas 52 mas J 15 7 18 000 80 13 H 13 9 83 000 12 4 K 14 1 40 000 30 5 K 13 7 52 000 20 5 LU 5 0 70 000 000 1 8 200 000 000 28 Table 4 2 Saturation magnitudes and maximum exposure times in JHK bands Filter 1s 5s 10s 30s 605 1205 3005 Max s 52 mas pixel scale for 0 3 seeing J 10 7 124 132 144 152 160 17 2 1000 H 10 6 123 131 144 15 4 16 6 200 K 10 0 11 7 12 5 137 146 15 5 17 4 420 K 9 9 11 6 124 13 7 145 155 184 330 20 mas pixel scale for AO correction J 113 130 138 150 157 165 17 5 6000 A 11 7 13 4
43. e for each of the standard settings for bands zJ to L They can be directly compared with the echellograms for the IRCS where you can also find the wavelength coverage for z and M bands http www naoj org staff pyo Echellogram Echellogram STD IRCS2 html html or http www naoj org bserving Instruments IRCS echelle pdf Echellogram STD IRCS pdf If you do not need to cover the whole band and want to find the optimal configuration you can use the Echelle Simulator for IRCS http www naoj org staff pyo Esimulator Esimulatorvl1 0 tar gz http www naoj org staff pyo Esimulator README 21 Table 3 9 Wavelength coverage for sets covering bands from zJ to H zJ band J band Set H Set H Ord Wavelength Disp Ord Wavelength Disp Ord Wavelength Disp Wavelength Disp no um A pix no pum A pix no pom A pix um A pix 48 1 163 1 191 0 276 41 1 361 1 395 0 326 31 1 793 1 838 0 440 49 1 139 1 167 0 273 42 1 329 1 361 0 319 32 1 736 1 780 0 427 1 749 1 791 0 416 50 1 116 1 144 0 269 43 1 298 1 330 0 313 33 1 684 1 726 0 415 1 695 1 737 0 404 51 1 094 1 121 0 264 44 1 268 1 300 0 307 34 1 634 1 676 0 404 1 646 1 686 0 394 52 1 073 1 100 0 260 45 1 240 1 271 0 301 35 1 588 1 628 0 393 1 598 1 638 0 384 53 1 053 1 079 0 256 46 1 213 1 243 0 295 36 1 543 1 580 0 383 1 554 1 592 0 374 54 1 033 1 059 0 251 47 1 187 1 217 0 289 37 1 502 1 540 0 374 1 512 1 549 0 365 55 1 015 1 040 0 245 48 1 163 1 192 0 283 38 1 462 1 499 0
44. e names coordinates the choice of observing mode and AO correction if desired 37GEM 0BJECT 37 Gem RA 065518 668 DEC 252232 515 EQUINOX 2000 0 First word is the object s alias name to which the system will refer later It must be with capital letters and numbers no spaces The name in parenthesis will appear later in the output file header under the OBJECT keyword The coordinates are in the format of hhmmss ss for RA and ddmmss ss for DEC For high proper motion targets add PMRA and PMDEC and put values in arcsec per year Put FIELD PA 0 for imaging or SLIT_PA 0 for spectroscopy either grism or echelle Se lection of one of the two is mandatory For imaging the camera s up direction is North when FIELD PA 0 without AO and FIELD PA 90 with the AO correction For spectroscopy SLIT_PA 0 means the slit is parallel to the North South direction For both cases the position angle PA is measured counterclockwise from North to East and is given in degrees To use the AO188 add GSMODE NGS for the natural guide star or GSMODE LGS for laser guide star When a separate tip tilt star need to be used for the AO correction you must define it as a separate object Definition of non sidereal targets must include COORD FILE TARGET 08 coords dat where the coords dat is a coordinate file that the user must prepare beforehand Please see http www naoj org bserving Telescope Tracking NonSidereal A complete line defining a targ
45. eld The second may be the same for imaging but for spectroscopy a proper one should be given to be found under the previously given URL The EXPTIME is just the exposure time in seconds of the test observation Checking the intensity on the test image will help to set the proper exposure time for the scientific observation defined by the GetObject command in order to reach the desired SNR and avoid saturation Examples CheckField DEF IMSTA DEF IM20H EXPTIME 5 a 5 second test for imaging in H band with AO in the 20 mas pixel scale CheckField DEF GRSTN DEF GRIZ N EXPTIME 10 a 10 s test for grism spectroscopy in the Iz band 52 mas pixel scale R4 narrow slit without guiding no AO SetupField DEF ECSTV DEF ECKP W EXPTIME 10 a 10 s test for echelle spectroscopy with K setting 0 54 wide slit guiding no AO GetObject This command is for making the observation by performing the proper dithering nodding pro cedure and taking the scientific data with a proper exposure time It may contain parameters that are typical for one observing mode only but also some that are common for all cases The first parameter DEF_Obsmode defines the observing mode It is composed of the part DEF_ followed by 39 e Two characters representing the mode IM for imaging GR for grism EC for echelle e A series of characters representing the nodding dithering sequence ST single frame all modes S5 5 point ditherin
46. element name 7 Camera Wheel 2 puka 2832 Camera Wheel 2 Hall Value 51100 Camera Wheel 2 motor position OPEN 1 Camera Wheel 3 element name 1 CW3PK 1 Camera Wheel 3 puka I_CW3HV 3070 Camera Wheel 3 Hall Value 48 I_CW3MP I_MFOCMC I_MFOCHV I_MFOCMP I_SCALE I_MDFMST I MFM18T I MFM1HV I MFM1MP I MFM2ST I MFM2HV I MFM2MP I SLWNM 1 SLWPK I_SLWHV I_SLWMP I_SPWNM I_SPWPK I_SPWHV I_SPWMP I_MECHAS I_MECHHV I_MECHMP I_MXDSAS I_MXDSHV I_MXDSMP I_CKMODE 5000 1000 2198 3436 Camera Wheel 3 motor position Focus Stage microns Focus Stage hall value Focus Stage motor position bbmas Pixel Scale LOW 7 Dual Flipmirror State IN Flipmirror 1 State IN OUT 3279 Flipmirror 1 Hall Value O FlipMirror 1 motor position IN Flipmirror 2 state IN OUT 4095 Flipmirror 2 Hall Value O FlipMirror 1 motor position 0 14x3 47 J SlitWheel element name 4 Slitwheel puka 2922 Slitwheel Hall Value 28700 SlitWheel motor position J Spectrograph Wheel element name 4 Spectrograph Filter Wheel Puka 3184 Spectrograph Filter Wheel Hall Value 13000 Spectrograph Filter Wheel Motor Position 2240 Echelle Arcsec 2367 Echelle Hall value 4978 Echelle Motor Position O Cross Disperser Arcsec 2052 Cross Disperser Hall value O Cross Disperser motor position ARC D Detector clock mode I_GRNS 40000 Detector global
47. en two consecutive targets 4 4 2 OTCs For each IRCS observing mode there is a tool available Overhead and Total observing time Calculator OTC that helps the user to estimate the time spent on each target depending on the exposure time number of coadds and dithering nodding scanning sequence Please note they may not work correctly under Microsoft IE browser Imaging OTC The OTC for the imaging mode is available at http www naoj org Observing Instruments IRCS camera IRCS_IMG_OC html 70990 mode Object Sky Sky Object is also possible 33 Set the readout mode Normal Thermal and the size of the area you will use Set the exposure time for one shot tone this is the time for a single opening of the shutter not necessarily the desired exposure time Set the number of coadds N number of exposures at one position Set the number of dithering positions Ng Your total integration time will be tone x Ne x Na and you will normally get Ng fits frames You may also set the number of dummyreads empty reads without integration The OTC will calculate the time necessary to move the telescope between dithering po sitions times for readout and fits file creation and will summarize everything The output includes e Time for single frame sec the time you will spend on a single dithering position ty OS Ne e Time for telescope moving in dithering Ng x 5 s e Total observing time total time necessar
48. erformance FOV field of view IMR image rotator IR infrared IRCS Infrared Camera and Spectrograph LGS laser guide star NDR non destructive readout NGS natural guide star OSF order sorting filter TT tip tilt Chapter 2 General information 2 1 Overall Description The Infrared Camera and Spectrograph IRCS is a multi purpose instrument designed to work in the near infra red regime from 0 9 5 6 um covering photometric bands from Iz to M It can be installed in the IR Nasmyth focus of the Subaru Telescope It consists of two modules the imaging camera and the echelle spectrograph both equipped with 1024x1024x27um ALADDIN III InSb detectors The instrument works with the AO188 adaptive optics system both in natural and laser guide star modes and is capable of providing diffraction limited images Spectroscopy can be performed either with the echelle spectrograph or with the camera using grisms Switching between observing modes is relatively fast and only requires moving the slit and or filter wheels to a different position The observing modes are described in more details in the following Chapter The choice of the observing mode is done by selecting an appropriate element on the slit wheel which is installed on the light path before any filter wheel Light is reflected to the camera section by a plain mirror or coronagraph mask for imaging reflective slits for grism spectroscopy or polarimetric masks
49. et may thus look as follows For imaging with AO188 laser guide star correction North up 37GEM OBJECT 37 Gem RA 065518 668 DEC 252232 515 EQUINOX 2000 0 FIELD PA 90 GSMODE LGS For spectroscopy of a high proper motion star with natural guide star AO correction at non zero position angle 37GEM OBJECT 37 Gem RA 065518 668 DEC 252232 515 PMRA 0 724 PMDEC 0 398 EQUINOX 2000 0 SLIT PA 66 6 GSMODE NGS Please note that one command is one line of the OPE file Don t break long commands as the ones above Remember to put Parameter List at the end of the object definitions to close the block 4 6 2 Observing procedure The main block of the OPE file is the lt Command gt block that is the true observing procedure script It normally starts with the following lines The name of the file is without 08 but 08 must be given in the definition 37 Table 4 4 Possible values of the DEF_Mode in the SetupField and CheckField commands Guiding and AO Imaging Grism sp Echelle sp With auto guiding DEF IMSTV DEF GRSTV DEF ECSTV No auto guiding DEF IMSTN DEF GRSTN DEF ECSTN With AO188 DEF IMSTA DEF GRSTA DEF ECSTA lt Command gt iHHi SetUp CheckOBE DEF IRST BootQDAS DEF IRST BootVGW DEF CMNT Choose a bright star MoveToStar DEF_CMNV Focusing AG FocusAGSequence DEF_CMNT Z TSCL Z DELTAZ 0 07 INSTRUMENT_DELTAZ 0 06 FocusAG DEF_CMNT Z TSCL Z DELTAZ 0 07 INST
50. for both imaging and spectropolarimetry The light is transmitted to the echelle section through one of the slits cut in reflecting mirrors In such configuration the camera section serves as the slit viewer 2 2 AO188 adaptive optics system The IRCS is currently fed by the AO188 adaptive optics system Even if the correction is not applied the light goes first through the AO optics The detailed description is provided at this website http www naoj org Observing Instruments A0 index html however we present some information here as they are required to prepare the IRCS proposal and observations It s also possible to remove AO188 so that light goes directly to IRCS This is however rarely done and must be done by the daycrew AO188 is equipped with a 188 element wavefront curvature sensor with photon counting APD modules and a 188 element bimorph mirror AO188 is installed at the IR Nasmyth platform of Subaru telescope and can be used in either natural guide star NGS or laser guide star LGS mode Diffraction limited spatial resolution can be achieved at KLM bands with a sufficiently bright guide star at good observing conditions At shorter wavelength 2 JH band high spatial resolution comparable to or even higher than the K band diffraction limit resolution can be achieved however the Strehl ratio is lower The maximum Strehl ratio so far achieved at K band is 0 55 at a 0 5 seeing condition For the NGS mode operation
51. g imag S9 9 point dithering imag D2 ABBA pattern spect D2XS1 OSO pattern spect D2XS2 OSSO pattern spect SS slit scanning spect e A single character representing the choice of guiding and AO as in Table 4 4 N without auto guiding no AO V with auto guiding no AO A with AO188 For example DEF_IMS5V 5 point dither imaging with auto guiding no AO DEF GRD2XS2N OSSO grism spectroscopy without auto guiding no AO DEF ECD2A ABBA echelle spectroscopy with AO For observations of non sidereal targets without AO always use the no guiding option DEF_ N The parameters EXPTIME COADDS and NDUMMYREAD may be used in each mode except for slit scanning EXPTIME defines the exposure time for a single shutter opening and can be a real number The other two are integers COADDS gives the number of exposures per position thus the integration time on one telescopes position is EXPTIME x COADDS NDUMMYREAD is optional ind most cases and set to O by default Also for non sidereal targets COORD FILE must be added in each mode Other parameters are observing mode dependent For imaging one can set for example e Dithering step in arcsec if not doing only a single frame for example DITH 5 0 e Pixel scale only with AO PIXSCALE 52MAS or PIXSCALE 20MAS e MODE AOP recommended or MODE TTNULL for AO correction e Rotator position angle in degrees if other than default for example FIELD
52. g a long integration one can use coadds shorter exposures that are later combined into one integration of a total desired exposure time for example a 2400 s integration can be made of 80 short ones 30 s each The final product is one frame that is already a combination of the 80 single images It is however possible to have each single coadd saved separately and obtain the final image as a data cube composed of 80 frames for the example above Please note that this is not the standard observing procedure and such data products take a lot of limited disk space Tf you re interested please contact Tae Soo Pyo pyo at naoj org before the proposal submission Please also note that the shortest available exposure time is limited and dependent on the sub array to be read out and the readout mode see Table 4 3 31 4 3 Dithering nodding object sky object and slit scanning The following procedures are commonly used in IR observations and contribute to the total time spent on a source Some time should be allowed for moving the telescope between the positions In the data reduction procedure the observations taken at each position are usually depending on the purpose combined into one The total integration time needed to reach a desired S N can then be split between each of the positions Observation at each position may consist of multiple coadds 4 3 1 Dithering in the imaging mode The vast majority of IR observations are d
53. g the relative offset in arcsec exposure time in seconds number of coadds 0 3 120 1 or 0 2 60 2 for example Note that the offsets count from the current position so if the first one was set to 0 25 one needs to set the second to 0 25 in order to come back to the first position The whole parameter may look as follows SCAN PAT 0 3 90 1 0 15 90 1 0 15 90 1 0 15 90 1 0 15 90 1 0 3 0 1 This will make a scan of a 0 6 area 0 3 around the target with a sequence of five 90 second exposures with a step of 0 15 and the telescope will come back to the initial position at the end e In echelle mode only EXPTIME_SV defines the exposure time of the slit viewer camera side in seconds It is important to keep it shorter than the normal EXPTIME which can be very short for bright objects Examples GetObject DEF_IMS5N EXPTIME 60 DITH 10 PIXSCALE 52MAS COORD FILE imaging with out AO188 correction 5 point dither with 10 step 60 s on each position 52 mas pix scale non sidereal target GetObject DEF_GRD2XS1A EXPTIME 120 DITH 3 0 RA OFFSET 30 DEC_OFFSET 1800 SLIT_PA 45 0 MODE AOP grism spectroscopy with AO188 correcion rotated slit OSO mode with 30 1800 sky offset and second object position 3 along the slit from the first one GetObject DEF_ECD2A EXPTIME 40 DITH 1 7 COADDS 3 PIXSCALE 52MAS MODE AOP echelle spectroscopy with AO ABBA nodding with 1 7 step 3 x 40 sec on each position Get
54. ht of a star can be blocked by one of the masks of the following diameters 0 15 0 6 and 0 8 arcsec 13 Table 3 3 Narrow band filters of the IRCS camera section Filter Center Width Sensitivity uJy for name um um uJy as 16 5 CH short 1 570 0 100 1 7 60 23 0 06 Hcont NB1550 1 549 0 018 0 25 CH long 1 690 0 100 1 7 60 23 0 06 Fe Il 1 644 0 026 3 3 120 47 0 40 NB2090 2 091 0 035 0 33 H 1 0 2 122 0 032 3 0 110 44 0 40 Br gamma 2 166 0 032 3 0 110 44 0 40 Kcont NB2315 2 314 0 030 0 63 H20 ice 3 050 0 152 41 2193 832 0 45 PAH 3 295 0 050 55 2900 1100 0 60 H3 3 413 0 022 Br alpha 4 052 0 060 140 7500 3000 0 60 Scanned at cold and tilted by 5 in IRCS except Br gamma scanned at room temperature Their location on an full size 20 mas pix image is presented in Figure 3 4 Figure 3 4 Coronagraphic masks of the IRCS camera section Numbers in parenthesis are the X Y pix coordinates of the centers of the masks in the 20 mas upper and 52 mas lower mode 14 ND Filter CaF2 1 2 lambda ircs011030_c2385 fits ircs011101 c4256 fits etc Figure 3 5 Two ghosts that appear when a bright source is observed through an ND filter 3 1 4 Image anomalies Apart from the latency and bad pixels there are no known image anomalies common to all the camera section settings There is one however that occurs when using the neutral density ND1 filter in
55. ion Center If you have already received your data at the summit please inform on the form as well The copy of your observation data will be available as following formats and please inform your preference on the request form e Sending either DAT or DLT media format visiting observes only Please choose a preferable media format and write your address on the request form We will send the item within a week e Obtaining data by yourself through Subaru Telescope Archive System STARS at Sub aru Telescope or MASTARS at Mitaka Office Also the PI of the proposal will obtain a notification email with instructions about how to access to the data at STARS MASTARS The IRCS data are subject to a common Subaru priority and archiving policy All raw scientific data will become publicly available at the SMOKA system after 18 months http smoka nao ac jp Chapter 3 Observing modes 3 1 Imaging The IRCS imaging camera offers two default pixel scales 20 and 52 mas pix producing fields of view of 21 and 54 respectively A third mode of 12 mas pix scale is also available upon request it is however not commonly used as it requires special preparations and science targets brighter than in the case of the other two on which we focus in this document ENTRANCE WINDOW TELESCOPE FOCUS i OFFNER SECONDARY DFFNER PRIMARY COLL I MATOR LENSES FILTER WHEELS INTERNAL TRUSS FLIP MIRROR 0 052
56. ithered several shorter exposures are made at slightly different positions and later combined into one image The IRCS offers four pre defined dithering patterns for imaging as presented in Fig 4 1 The step between positions normally the same in X and Y is defined by the user but the default value is 10 asec It is also possible to dither manually by introducing X and Y offsets before every exposure In such case keep in mind that the offsets are not recorded i e when the first offset was set to AX 10 in order to come back to the original position one needs to set the second offset to AX 10 D9 5 9 D5 ko ok ok o xk Ok o k k xk E I I Figure 4 1 Pre defined dithering standard S and diamond D patterns The parameter d is the step of the dither in asec which can be defined by the user 4 3 2 ABBA slit nodding Even with the 0 15 slit the spectral resolution of the IRCS grisms is not high enough to work effectively between the OH lines Good removal of these lines is an essential part of obtaining high quality scientific data and this is usually performed by nodding the target along the slit on a timescale no longer than the typical variability timescale of the OH lines This procedure is also performed with the echelle observations where OH lines removal is not that critical yet still important The target is observed in two positions A and B se
57. ld be used to simulate the IRCS grism spectroscopy http www naoj org Observing Instruments IRCS grism spica html It is written in Java and Swing and requires at least Java 1 1 2 compatibility If run correctly the following web page with instructions should appear automatically http www naoj org java spica html 4 1 3 Echelle spectroscopy Sky background High resolution of IRCS echelle spectra allow for observations for which the OH airglow lines are resolved and night sky continuum is visible Its level is however not well determined typically 1000 photons m asec um as it is less than the detector s dark current Thus the observations in JHK are alway detector limited To ensure proper extraction of the OH lines we suggest exposure times no longer than 900 s in J 200 sin A and 300 sin K band The OH lines may also serve as additional wavelength calibrators Their list is presented in the Appendix see page 50 See also the echellograms links in pages 21 and 24 In general we also suggest not to make single exposures longer than 900s Please use coadds if you need to integrate longer Please also remember about the detectors non linearity and keep the signal level below 6000 ADU In the thermal IR bands L and M the sky and instrument background is always high and observations become background limited after 30 sin L and 4 s in M A point source of L 1 mag will saturate after 1 s Echelle exposure time calc
58. m 1 21469 AU1 offset X on sky arcsec 0 37485 AU1 offset Y on sky arcsec 2 07009 AU focus mm 3E 05 AU tilt X deg 1E 05 AU tilt Y deg 6 64442 AU1 M1 X actuator mm 12 7153 AU1 M1 Y actuator mm 46 3265 AU M1 Z stage mm 6 66435 AU1 M2 X actuator mm 13 1675 AU1 M2 Y actuator mm 488 58 AU1 guide star X pos pix 518 08 AU1 guide star Y pos pix 1E 05 AU2 offset X mm 1E 05 AU2 offset Y mm 2E 05 AU2 offset X on sky 2E 05 AU2 offset Y on sky 1 81999 AU2 focus mm 0 AU2 tilt X deg 1E 05 AU2 tilt Y deg 12 1983 AU2 M1 X actuator 12 4344 AU2 M1 Y actuator arcsec arcsec nm nm 45 D_AU2M1Z D_AU2M2X D_AU2M2Y D_AU2GSX D_AU2GSY D_HWNAP D_HWNAPP D_HWLAP D_HWLAPP 1 67855 AU2 M1 Z stage mm 12 4463 AU2 M2 X actuator mm 12 2699 AU2 M2 Y actuator mm 418 5 AU2 guide star X pos pix 610 8 AU2 guide star Y pos pix AASEC HOWFS NGS aperture name 49 14 HOWFS NGS aperture position mm AASEC HOWFS LGS aperture name 17 9 HOWFS LGS aperture position mm D HWAD OUT HOWFS ADC stage position IN OUT HWADP D HWADST D HWADMD D HWADA1 D HWADA2 D HWADFC D HWADRA D HWADDC D HWADPA D HWABS D_HWABSP D_HWAF1 D_HWAF1P D_HWAF2 D_HWAF2P D_HWHBS D_HWHBSP D_VMAP D_VMAPS D_HWPBS D_HWPBSP D_HWLAZ D_HWLAZP D_HWLAF D_HWLAFP D_HWLASH D_HWAPDA D_LWAP1 D_L
59. meters html 050810 11 Table 3 1 Basic parameters of the IRCS imaging camera Mode 20 mas 52 mas Pixel scale FOV Gain Dark current Readout noise Saturation level Readout rate 20 57 0 04 mas 52 77 0 04 mas 21 06 arcsec 54 04 arcsec 5 6 e ADU 0 1 e s 43e rms 123 000 e 0 41 s standard 0 12 s fast The 12 mas mode has the pixel scale of 11 94 0 01 mas and a with AO to convert for case without AO divide these values by 1 007 N field of view 12 22 arcsec for the 12 mas mode gt per NDR readout noise per frame readout noise per NDR sqrt NDR for the full 1K x 1K array size 300 E 2 o E 200 E o E D g 100 Eu Ne ae 0 a of sz o O 0 5000 10000 15000 Signal ADU Figure 3 3 Non linearity of the IRCS imaging detector The detector shows a significant level of non linearity at high ADU Fig 3 3 To achieve linearity down to 1 we recommend a maximum signal value 4000 ADU 22 400 e per exposure For L and M bands the signal level of 7000 ADU 39 200 e can be allowed with less than 3 non linearity because of very high background level Keep in mind that you do not have to read out the whole 1024x1024 chip but reading in sub arrays is possible and even mandatory in some modes or filters like the L filter This of course results in shorter read out times and lower overheads It is not possible to
60. ne of the OTCs 34 The ton is t tone X Ne 5s x Np Use this relation to estimate the overheads for the slit scanning Note that the total integration time is tror ton tone X Ne X Np but in OSO OSSO it corresponds to the sum of object and sky integration times Echelle OTC The OTC for the echelle spectroscopy mode is available at http www naoj org bserving Instruments IRCS grism IRCS ECH OC html The input is almost the same as for the grism ETC tone Ne observation mode but it in cludes the slit viewer SV exposure time tsv Note that each sequence ABBA OSO OSSO requires four SV exposures Again number of positions N 4 for ABBA and OSSO and 3 for OSO The total integration times on target and sky are calculated in the same way as for the grism observations You will get N fits frames with spectra but also four SV frames The output looks somewhat similar to the imaging and grism OTCs and includes e Time for single frame sec the time you will spend on a single dithering position t4 gt Done Ne e Time for telescope moving in dithering N x 5 s e Times for one and four SV frames e Total observing time total time necessary to perform the observation tror e Total overhead time top The ton is ty tone X Ne 5s x Np Use this relation to estimate the overheads for the slit scanning Note that the total integration time is tror ton tone X Ne X Np but in OSO OSSO i
61. on matrix PC002002 0 999989 Coordinate translation matrix CTYPE1 DEC TAN Pixel Coordinate System CTYPE2 RA TAN Pixel Coordinate System CUNIT1 degree CRVAL1 units CUNIT2 degree CRVAL2 units FILTERO1 27 First filter element WAVELEN 0 0000 Wavelength at detector center microns SLTCPIX1 0 00000000 Slit detector center pixel SLTCPIX2 0 00000000 Slit detector center pixel SLT LEN 3 51652293 Slit length arcsec SLT WID 0 13954440 Slit width arcsec SLT PA 90 00000000 Slit Position Angle SLTC RA 0 00000000 RA of slit center degree SLTC DEC 0 00000000 DEC of slit center degree DISPERSR ECHELLE 7 Disperser name DISPAXIS 2 Number of dispersing axes D MODE NGS Guide star mode NGS LGS LGSwoNGS NGS NGS D ENSHUT OPEN Entrance shutter position OPEN CLOSE D ESHUTP 162 Entrance shutter position mm D_CLD1 OFF CAL LD 655nm ON OFF D CLD2 OFF CAL LD 1550nm ON OFF D_CLD3 70 7 CAL LD 589nm ON OFF D_CALX 0UT 7 CAL X stage position D_CALXP O CAL X stage position mm D_CALZ 0UT CAL Z stage position D_CALZP 100 CAL Z stage position mm D_IMR TRACK IMR tracking status TRACKING SLEWING STAND BY D_IMRMOD SID IMR tracking mode SID NON SID ADI STOP OTHER D_IMRANG 16 8577 IMR angle deg D_IMRPAD 0 27 IMR position angle of dec axis deg D_IMRPAP 160 63 IM
62. on of the IRCS Three elements need to be set reflective slit on the slit wheel an order sorting filter and a grism both on filter wheels The final spectral resolution and wavelength coverage are dependent on each of the three elements and the pixel scale selected 3 2 1 Reflective slits There are two reflective slits available in the slit wheel They are the main factor that deter mines the output spectral resolution The Reflective 3W R3W is composed of 3 elements of different thickness fixed in mm that mimic three different slit widths 0 9 0 45 and 0 6 but only the 0 45 is available in the 20 mas mode The Reflective 4 slit R4 has four such elements 0 3 0 15 0 1 and 0 23 the last three being available in the 20 mas mode As it offers narrow widths it should be exclusively used with the AO188 otherwise the loss of the flux will be significant The selection between the elements is done under the imaging mode by placing the target in a corresponding acquisition point certain X and Y values in pixels and then the R3W or R4 is introduced in the light path Nodding along the slit is frequently performed in IR observations but note that some parts of slits are of worse quality or fall on bad pixel See Figure 3 6 for details The maximum allowed length is 20 arcsec 10 for 0 1 and 0 15 but the lengths of the most useful parts are given in Tables 3 4 and 3 5 Remember that the grism mode does not
63. parated by a value defined by the user The sequence of observation is ABBA 32 4 3 3 Object Sky Object The sky removal in case of observations of extended objects is done by the Object Sky Object OSO observing procedure The observer can set the offset in RA and DEC between Object and Sky Object can be returned at a different position on the slit if you set the dithering parameter Its value should be small in comparison to the Object Sky offset 4 3 4 Slit scanning Large areas can be mapped spectroscopically For this one can work in the slit scanning mode The scanning is done in the direction perpendicular to the slit and the relative offset exposure time and number of coadds for each position 4 4 Overheads and total observing time calculators 4 4 1 Common overheads Listed below are overheads that are common for all observing modes e Field setup target acquisition per each target 3 5 min for imaging 10 15 min for spectroscopy e Telescope pointing time 1 min for dAZ 30 degree e Focus adjustment usually 3 times per a night 10 min per one time e If you use AO correction for AO188 parameter adjustment 15 min per each target e Filter change less than 1 min Please note that focus and AO188 adjustment are dependent on current weather conditions and their stability in bad or unstable conditions these overhead times may increase drastically The AO setting time will also depend on brightness difference betwe
64. per line and sends it to the control system It is worth to note that the commands may be edited during the night for example the exposure time or slit position angle may be adjusted Some of the keywords that compose a command are mandatory others can be omitted or added In each observing mode you can choose e With or without auto guiding e If with on sidereal or non sidereal object e With or without AO correction e If with using laser LGS or natural guide star NGS Every OPE file should begin with a header similar to the following Header Observation File Name user ope file ope Observation File Type OPE Observation Start Date 2014 12 09 Observation Start Time 00 15 00 Observation End Date 2014 12 09 Observation End Time 06 00 00 HEC 0 14 slit ABBA J band only lt Header gt Where the file name dates and times should be changed appropriately Note that the blocks of the OPE file are defined with lt gt and lt gt as in HTML and the line that starts with is a comment that is not read by the system 4 6 1 List of targets Second part of the OPE file is the list of the objects to be observed It is a part of the block called Parameter List that needs to start as follows lt Parameter_List gt LOAD ircs mod prm LOAD ircs_mec prm 36 DEF_AOLN 0BE_ID A0188 OBE_MODE LAUNCHER DEF_AOST 0BE_ID A0188 OBE_MODE A0188_SETUP Then comes a series of lines that define each object They contain th
65. r TIMESYS UTC Time system used in this header 42 DATE OBS 2014 12 09 UT date of Observation yyyy mm dd EXP1TIME 15 0000 Integration time in seconds EXPTIME 60 0000 Integration time in seconds COADD 4 Number of Coadds COADDS 4 Number of Coadds DET NSMP 16 Number of Non Destructive Reads I_NDR 16 Number of Non Destructive Reads NDR 16 Number of Non Destructive Reads UT STR 15 46 28 16 Start Exposure at UTC HH MM SS SS UT 15 47 11 08 Typical UTC at exposure HH MM SS SS UT END 15 47 54 37 End Exposure at UTC HH MM SS SS HST 05 46 28 16 7 Start exposure at HST HH MM SS SS DET TMP 27 99 Detector Temperature BIN FCTi 1 Binning factor of the X axis BIN FCT2 1 Binning factor of the Y axis BLANK 32768 Value used for null pixels BUNIT ADU Unit of original pixel values INSQ 1 Number of the frame in the sequence I NSQMAX 1 Maximum number of the sequence SLIT 0 14x3 47 J Entrance slit identifier PROP ID 7014432 Proposal ID DATASET NOP Id of Observation Dataset DET ID 2 Detector Id 1 CAMERA 2 SPECTROGRAPH EQUINOX 2000 Standard FK5 years UT1 UTC 0 433 Difference between UT1 and UTC MJD 57000 65725694 Modified Julian Day at typical time LST 10 37 16 30 Typical local sidereal time during exposure WCS ORIG SUBARU Toolkit Origin of World Coordinate System RA 10 56 28 557
66. reset pulsewidth ns I_BGRFL I_BGRRT I_BGRDL I_BGRPW I_SLWCNT I_VGGCL T Backgroud Resets flag T Yes F No 900 Detector backgroud resets rate ms 10 Detector background reset delay ms 40000 Backgroud Resets pulsewidth nanoseconds 16 Number of detector Slow Counts 3 25 Detector VGGCL volts I_VDET 3 45 Detector VDET volts I_VDDUC I_VBIAS 3 75 Detector VDDUC volts 0 30 Detector Bias I_VDET I_VDDUC volts GAIN 3 8 AD conversion factor electron ADU I_PGAIN I_NSUBAR I_SAR1CX I_SAR1CY I_SAR1WD I_SAR1HT 18 289 Gain of Redline Preamp Boards 1 Number of Sub Arrays O Subarray 1 center x pixel coord O Subarray 1 center y pixel coord O Subarray 1 width O Subarray 1 height 49 I_NDRASZ 0 00000000 Nod R A size arc seconds I_NDDCSZ 0 00000000 Nod DEC size arc seconds I_DTHSZ 1 70000000 Dither step size arc seconds I_DTHPAT ABBA Dither pattern shape I DTHNUM 4 N positions in dither I_DTHPOS A1 Dither position END 5 2 OH emission lines Table 5 1 The list of OH emission lines that may be used for wavelength calibration of echelle spectra in the zJ K range The accuracy in X and Y is 10 pix Order Wavelength um Intens X pix Y pix zJ set 52 1 08312 0 40 353 3 240 6 52 1 08993 0 10 612 5 261 1 52 1 09273 0 24 722 0 270 0 52 1 09523 0 10 821 4 278 2 51 1 09523 0 10 26 0 279 9 52 1 09763 0 35
67. s a function of wavelength is presented in Fig 3 10 and its position angle in Fig 3 11 It was measured that the position angle of instrumental polarization parallactic angle 90 3 4 3 Unpolarized and standard stars To calibrate your science observations please observe polarized and unpolarized standard stars Such objects can be found for example in http people bu edu clemens mimir polarimetric standards htm http www eso org sci facilities paranal decommissioned isaac tools swpl html http adsabs harvard edu abs 1992ApJ 386 562W 26 Measured Expected Tertiary Mirror e Degree of Polarization 1 15 2 25 Wavelength micron Figure 3 10 Degree of instrumental polarization introduced by the tertiary mirror 135 Stokes U Position Angle of Polarization degree o i so 15 0 5 0 0 5 1 15 180 135 90 45 O 45 90 135 180 Stokes Q Parallactic Angle 90 degree Figure 3 11 Position angle of instrumental polarization 27 Chapter 4 Preparing and executing observations 4 1 Exposure times and their calculators This section contains information regarding the exposure times for various IRCS observing modes as well as links and short instruction for exposure time calculators This is important but not the only factor that determines the total time required for observations of a particular object See further sections to learn about coadds dithering and overhea
68. separately for each setting A short series of lamp ON and OFF frames are taken single images combined and the resulting median ON and OFF images subtracted to get the final one As for the imaging dark current and bias frames are not in the standard routine The wavelength calibration is initially based on spectra of an Ar lamp taken at the begin ning or end of the night separately for each setting A short series of lamp ON and OFF frames are taken single images combined and the resulting median ON and OFF images 18 Table 3 6 Corrections in sensitivity for a point source as a function of seeing slit width and pixel scale Corrections for 20 mas Corrections for 52 mas Seeing 0 10 0 15 0 30 0 60 0 90 0 15 0 30 0 60 0 90 0 06 4 8 5 0 51 449 47 42 4 2 41 39 0 2 35 39 443 43 41 43 2 34 436 434 0 5 2 0 2 5 3 2 3 6 3 6 1 8 2 4 2 9 42 9 0 7 1 5 20 42 7 3 2 3 3 41 5 2 1 2 5 42 6 1 0 1 0 15 2 2 2 7 2 9 0 9 1 6 2 0 21 subtracted to get the final one The wavelength solution may also be based on the atmospheric bands in the L band but not on the OH emission lines due to the low spectral resolution See Section 5 3 in the Appendix 3 2 5 Grism data reduction A document presenting a typical procedure to reduce and analyze the IRCS grism spectra has been prepare
69. t corresponds to the sum of object and sky integration times 4 4 3 Polarimetry a special case The observation procedure to achieve the accurate calibration of the instrument polarization is more complicated and requires larger overheads In order to set practical observation pro cedure and consuming time users should contact Tae Soo Pyo pyo at naoj org before the proposal submission 4 5 Spectral format calculators Although already mentioned in this document we d like to remind you that the spectroscopic observations can be simulated with the following tools e SPICA for grism http www naoj org Observing Instruments IRCS grism spica html e Echelle Simulator http www naoj org staff pyo Esimulator Esimulatorv1 0 tar gz and http www naoj org staff pyo Esimulator README 35 4 6 OPE file All observations with the Subaru telescope are made by executing commands written in Ob servation Procedure Execution OPE files These files include commands that serve for posi tioning the telescope setting a proper instrument configuration take an exposure etc as well as a list of all the targets that are to be observed IRCS users should prepare such file and send it to their support astronomer in advance See also http www naoj org staff pyo IRCS Preparation OPE for IRCS html http www naoj org bserving Instruments IRCS Template ope The execution of each command is done by the instrument operator who marks a pro
70. the first filter wheel two ghosts appear when a bright source is observed Their location is shown in Figure 3 5 Before 2006 when the instrument was installed in the Cassegrain focus there were two more ghosts visible produced by the beam splitter and compensator After moving to the Nasmyth focus these two elements are not in use any more and the problem does not exist 3 1 5 Imaging calibrations Calibrations for the imaging observations include flat field images For the 52 mas scale dome flats are taken by observations of a uniformly illuminated screen installed inside the dome For the 20 mas an internal calibration source is inserted In case of LUM imaging sky flats are taken regardless of the pixel scale Exposuress are done at the beginning or end of the night separately for each setting A short series of lamp ON and OFF frames are taken single images combined and the resulting median ON and OFF images subtracted to get the final one Dark current frames are not in the calibration plan It is possible to make bias frames but they are not in the standard routine 3 1 6 Imaging data reduction A document presenting a typical procedure to reduce and analyze the IRCS imaging data has been prepared http www naoj org bserving DataReduction Cookbooks IRCSimg 2010jan05 pdf 15 3 2 Grism spectroscopy The low resolution R 100 2000 spectroscopy is performed in the camera secti
71. ts for example However frequent changes of readout mode will result in detector problems and unnecessary delays 3 1 2 Filters Three filter wheels offer a wide selection of broad and narrow band astrophysical as well as ND1 filters Tables 3 2 and 3 3 summarize the characteristics of broad and narrow band astrophysical filters respectively All sensitivities are for 50 detections in 1 hour of on source integration with the infrared secondary mirror They assume background limited performance see Section the guide to exposure times Point source sensitivities assume 0 5 seeing and a 1 0 diameter extraction aperture which means they do not assume AO correction With a full correction they would improve by 1 2 mag Extended source sensitivities are given per pixel the first column is for the 20 mas pixel scale the second for the 52 mas pixel scale Binning over N pixels will improve the sensitivity by 1 25 log N mag Observers should be aware that variations in the strength of the OH air glow can cause changes of up to 1 mag in the sky background with significant changes in sensitivity of the broad band filters The transmission curves of almost every filter are available as plots or ASCII lists kindly provided by Alan Tokunaga of the IRTF from the following URL http www naoj org bserving Instruments IRCS camera filters 3 1 3 Coronagraphy Simple coronagraphy is possible in the imaging mode with both pixel scales The lig
72. ulator ETC The ETC for the echelle section of the IRCS is available here http www naoj org Observing Instruments IRCS echelle IRCS_Echelle_ETC html 30 Table 4 3 Shortest exposure times in seconds for normal and thermal fast readout modes as a function of sub array size Sub array Normal Thermal 10242 0 41 0 119 896 0 33 0 096 768 0 26 0 076 640 0 20 0 058 512 0 14 0 042 384 0 10 0 029 2562 0 06 0 018 1282 0 029 0 009 642 0 017 0 006 Please note it may not work correctly under Microsoft IE browser Please select point or extended source The AO188 correction next choice is important for point sources only and highly recommended with the narrowest 0 14 slit highest resolution Set the band target brightness in magnitudes or mag asec slit width resolution and the S N you wish to reach If not using AO choose the seeing With AO correction the ETC will always use 0 5 You can also choose binning along the dispersion direction remember that the spectrum is already properly sampled with R 20 000 As the output the ETC will give you the integration time required to achieve the desired S N together with information about sensitivity in the selected band and corrections Note that the S N is per collapsed pixel i e per pixel of an extracted spectrum 4 2 Coadds and data cubes In order to keep the background level on a sufficient level as well as not to saturate the source durin
73. y is available with zJH and HK grisms in 52 mas mode only Please be advised that circular polarimetry is not available Users should contact Tae Soo Pyo pyo at naoj org for more detailed information The basic specifications are summarized in Table 3 13 Sample images from the two modes both in 52 mas pixel scale are presented in Figure 3 8 25 Degree of polarization Degree of polarization 0 10 20 30 40 50 60 70 80 90 a 1 12 1 4 AOIMR angle degree 1 6 1 8 2 22 24 26 Wavelength micron Figure 3 9 Efficiency of polarization as a function of IMR angle of the AO188 measured in various bands as a degree of polarization of a previously polarized light Left for the imaging polarimetry right for the spectropolarimetry The highest efficiency is achieved for IMR set to O or 90 degrees 3 4 1 Polarization efficiency There is a strong dependence of the polarization efficiency on the image rotator IMR angle of the AO188 The highest efficiency in both modes is reached for IMR angles around 0 or 90 degrees and the observations are made only in these positions The effect is presented in Figure 3 9 Measurements were done using a WPU polarizer and were not corrected for its own polarization angle 3 4 2 Instrumental polarization Preliminary observations of unpolarized stars show that the tertiary mirror is responsible for the majority of instrumental polarization The degree of instrumental polarization a
74. y to perform the observation tror e Total overhead time top Note that the total integration time is tror tog tone X Ne x Na Caution Due to short observation times imaging in L M bands requires substantial relative overheads The total required time is roughly 3 times larger than the time devoted for the observation itself Grism OTC The OTC for the grism spectroscopy mode is available at http www naoj org bserving Instruments IRCS grism IRCS GRS OC html Set the exposure time for one shot tone this is the time for a single opening of the shutter not necessarily the desired exposure time Set the number of coadds N number of exposures at one position Set the observation mode ABBA OSO or OSSO The OSO sequence corre sponds to N 3 positions ABBA and OSSO to N 4 you will get N fits frames The total integration time on target will be tone x Ne x 4 in ABBA and tone x Ne x 2 in OSO OSSO The total integration time on sky will be tone x Ne in OSO and tone x Ne x 2 in OSSO You may also set the number of dummyreads empty reads without integration The output looks similar to the imaging OTC and includes e Time for single frame sec the time you will spend on a single dithering position t4 OS Ne e Time for telescope moving in dithering N x 5 s e Total observing time total time necessary to perform the observation tror e Total overhead time toy Data cubes are not implemented in no

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