9457( 3) - 03/19/02 11:07 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9457 Version: 3 Check-in Date: 19-Mar-2002 11:06:48 1.Proposal Title: NICMOS Observations of the Galactic Center: Environment of a Black Hole ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Marcia Rieke University of Arizona CoI: George Rieke University of Arizona N ------------------------------------------------------------------------------------ 5. Abstract Intensive observation of the Galactic Center in recent years has shown conclusively that the Milky Way is home to a 2.5*10^6Msun black hole. Infrared observations of the stellar population have revealed a bright, young stellar cluster nearly coincident with the Center. We still do not know how the black hole influences its surroundings beyond the stellar dynamics very close to the hole. We do not even know whether the Milky Way has a core similar that seen in massive bulges or has a mass distribution that follows a power-law right into the center. We propose to use NICMOS to measure the central surface brightness profile of the galaxy, and to measure proper motions over the critical volume where the transition from black hole -dominated gravitational field to stellar mass- dominated gravitational field occurs. The data collected to investigate these issues will also shed light on the main sequence associated with the young stellar cluster and whether it formed in situ or elsewhere in the galaxy. ------------------------------------------------------------------------------------ 9457( 3) - 03/19/02 11:07 - [ 2] Observations Description ------------------------ Need for NICMOS Data: The Galactic Center has been little studied at wavelengths shorter than 2.2Mu m from the ground because adaptive optics work less well at J(1.25Mu m) and H(1.6Mu m). The proposed observations must be done with NICMOS because with WFC3 with its 0.12"/pixel plate scale will not sample the PSF adequately for the demanding PSF fitting required for this crowded region. WFC3 also does not have any sensitivity beyond 1.8Mu m. Core Radius Measuremen: Positions centered 20" and 60" from SgrA* will be observed on separate orbits in F110W, F160W, and F222M. A four position dither using .34" steps and a MULTIACCUM pattern giving an exposure time of 290 seconds per dither position will be used for F110W. The same dither pattern but a 26-second exposure per dither position will be used for F160W and 72 seconds per dither position will be for F222M. The telescope will then be offest by the small amounts needed to move to the Center or to the "near" field. The images needed to get good depth at F110W will be acquired using the same pattern as described above. An F160W exposure as described above which is identical to the ones used in Program 7222 will be taken and used to check for variability. Including the telescope offset overhead, data at the 20" position and the Center will take one orbit as will the data at 60" and the "near" field. Proper Motion Measurement The NIC1 observation using F145M will be taken using the same procedure as was used in Program 7225. Four NIC1 positions covering 19"x19" will be observed with the location of SgrA* in successive corners of the image. A fifth image with SgrA* in the center completes the one orbit observation. Each position is observed using a four position dither with 0.0645" steps and using a MULTIACCUM readout pattern. Real Time Justification ----------------------- The NIC 1 observation using F145M for proper motions should be taken as close to an ORIENT of 45.2degrees as possible to match the previous observation in Visit 5 of program 7225 (Mar 2, 1998, the first epoch of the old data taken in good focus). Using the same orientation as an older observation will minimize problems associated with camera distortions. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9457( 3) - 03/19/02 11:07 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GALCENTER-1 STELLAR CLUSTER, RA=17H 45M 40.4S +/- 0.05S, DEC= J2000 K = 15+/-1 NUCLEUS -29D 0' 28" +/- 0.5" Coordinate Source: OTHER_SOURCE 2 GALCENTER-2 STELLAR CLUSTER, RA=17H 45M 40.0S +/- 0.05S, DEC= J2000 K = 15+/-1 NUCLEUS -29D 0' 33" +/- 0.5" Coordinate Source: OTHER_SOURCE 3 GALCENTER-3 STELLAR CLUSTER, RA=17H 45M 39.6S +/- 0S, DEC=- J2000 K = 15+/-1 NUCLEUS 29D 0' 28" +/- 0" Coordinate Source: OTHER_SOURCE 4 GALCENTER-4 STELLAR CLUSTER, RA=17H 45M 40.0S +/- 0S, DEC=- J2000 K = 15+/-1 NUCLEUS 29D 0' 23" +/- 0" Coordinate Source: OTHER_SOURCE 5 GALCENTER STELLAR CLUSTER, RA=17H 45M 40.05S +/- 0S, DEC=- J2000 K = 15+/-1 NUCLEUS 29D 0' 27.9" +/- 0" Coordinate Source: OTHER_SOURCE 6 NEARCENTER STELLAR CLUSTER RA=17H 45M 47.1S +/- 0S, DEC=- J2000 K = 15+/-.5 28D 59' 11" +/- 0" Coordinate Source: OTHER_SOURCE 7 20-ARCSEC-GC STELLAR CLUSTER RA=17H 45M 41.2S +/- 0S, DEC=- J2000 K = 15+/-.5 29D 0' 15.1" +/- 0" Coordinate Source: OTHER_SOURCE 8 60-ARCSEC-GC STELLAR CLUSTER RA=17H 45M 43.6S +/- 0S, DEC=- J2000 K = 15+/-.5 28D 59' 49.5" +/- 0" Coordinate Source: OTHER_SOURCE 9457( 3) - 03/19/02 11:07 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type NIC-SPIRAL-DITH Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.0645 Coordinate_Frame POS-TARG Pattern_Orient 0 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type NIC-SPIRAL-DITH Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.375 Coordinate_Frame POS-TARG Pattern_Orient 0 Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 9457( 3) - 03/19/02 11:07 - [ 5] Visit: 01 Visit Priority: Visit Requirements: SCHED 30% ORIENT 40D TO 50D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 GALCENTER-1 NIC1 MULTIAC NIC1-FI F145M 14500 SAMP-SEQ=STEP8,NSAMP=17 1 DEF PATTERN 1 10 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 20 GALCENTER-2 NIC1 MULTIAC NIC1-FI F145M 1.45000 SAMP-SEQ=STEP8,NSAMP=17 1 DEF PATTERN 1 20 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 30 GALCENTER-3 NIC1 MULTIAC NIC1-FI F145M 1.45000 SAMP-SEQ=STEP8,NSAMP=17 1 DEF PATTERN 1 30 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 40 GALCENTER-4 NIC1 MULTIAC NIC1-FI F145M 1.45000 SAMP-SEQ=STEP8,NSAMP=17 1 DEF PATTERN 1 40 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 50 GALCENTER NIC1 MULTIAC NIC1-FI F145M 1.45000 SAMP-SEQ=STEP8,NSAMP=17 1 DEF PATTERN 1 50 CUM X ------------------------------------------------------------------------------------------------------------------------------------ 9457( 3) - 03/19/02 11:07 - [ 6] Visit: 02 Visit Priority: Visit Requirements: SCHED 30% ORIENT 0D TO 359D On Hold Comments: Additional Comments: Core radius program Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 GALCENTER NIC2 MULTIAC NIC2 F110W 1.10000 SAMP-SEQ=STEP16,NSAMP=16 1 DEF PATTERN 2 15 CUM ------------------------------------------------------------------------------------------------------------------------------------ 20 GALCENTER NIC2 MULTIAC NIC2 F160W 1.60000 SAMP-SEQ=STEP8,NSAMP=8 1 DEF PATTERN 2 20 CUM ------------------------------------------------------------------------------------------------------------------------------------ 30 20-ARCSEC-G NIC2 MULTIAC NIC2 F110W 1.10000 SAMP-SEQ=STEP16,NSAMP=17 1 DEF PATTERN 2 30 C CUM ------------------------------------------------------------------------------------------------------------------------------------ 40 20-ARCSEC-G NIC2 MULTIAC NIC2 F222M 2.22500 SAMP-SEQ=STEP8,NSAMP=14 1 DEF PATTERN 2 40 C CUM ------------------------------------------------------------------------------------------------------------------------------------ 50 20-ARCSEC-G NIC2 MULTIAC NIC2 F160W 1.60000 SAMP-SEQ=STEP8,NSAMP=8 1 DEF PATTERN 2 50 C CUM ------------------------------------------------------------------------------------------------------------------------------------ 9457( 3) - 03/19/02 11:07 - [ 7] Visit: 03 Visit Priority: Visit Requirements: SCHED 30% ORIENT 0D TO 359D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 30 NEARCENTER NIC2 MULTIAC NIC2 F110W 1.10000 SAMP-SEQ=STEP16,NSAMP=16 1 DEF PATTERN 2 30 CUM ------------------------------------------------------------------------------------------------------------------------------------ 40 NEARCENTER NIC2 MULTIAC NIC2 F160W 1.60000 SAMP-SEQ=STEP8,NSAMP=8 1 DEF PATTERN 2 40 CUM ------------------------------------------------------------------------------------------------------------------------------------ 50 60-ARCSEC-G NIC2 MULTIAC NIC2 F110W 1.10000 SAMP-SEQ=STEP16,NSAMP=17 1 DEF PATTERN 2 50 C CUM ------------------------------------------------------------------------------------------------------------------------------------ 60 60-ARCSEC-G NIC2 MULTIAC NIC2 F222M 2.22500 SAMP-SEQ=STEP8,NSAMP=14 1 DEF PATTERN 2 60 C CUM ------------------------------------------------------------------------------------------------------------------------------------ 70 60-ARCSEC-G NIC2 MULTIAC NIC2 F160W 1.60000 SAMP-SEQ=STEP8,NSAMP=8 1 DEF PATTERN 2 70 C CUM ------------------------------------------------------------------------------------------------------------------------------------ 9457( 3) - 03/19/02 11:07 - [ 8] Summary Form for Proposal 9457 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures NIC1-FIX NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC1 NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SAMP-SEQ=STEP8 NSAMP=17 NSAMP=16 NSAMP=8 SAMP-SEQ=STEP16 NSAMP=14 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 30% ORIENT 40D TO 50D PATTERN 1 10 PATTERN 1 20 PATTERN 1 30 PATTERN 1 40 PATTERN 1 50 SCHED 30% ORIENT 0D TO 359D PATTERN 2 15 PATTERN 2 20 PATTERN 2 30 PATTERN 2 40 PATTERN 2 50 PATTERN 2 60 PATTERN 2 70 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F145M F110W F160W F222M ------------------------------------------------------------------------------------------------------------------------------------ Target Names GALCENTER-1 GALCENTER-2 GALCENTER-3 GALCENTER-4 GALCENTER 20-ARCSEC-GC NEARCENTER 60-ARCSEC-GC ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 14500 1.45000 1.10000 1.60000 2.22500 ------------------------------------------------------------------------------------------------------------------------------------