10824( 6) - 10/13/06 16:36 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 10824 Version: 6 Check-in Time: 13-Oct-2006 20:35:25 STScI Edit Number: 1 Title Measuring the Shape and Orientation of the Galactic Dark-Matter Halo using Hypervelocity Stars ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO 15 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Oleg Y. Gnedin The Ohio State University Research Foundation CoI: Dr. Jay Anderson Rice University N CoI: Dr. Andrew Gould The Ohio State University Research N Foundation CoI: Mr. Jose Luis Prieto The Ohio State University Research N Foundation CoI: Dr. Krzysztof Stanek The Ohio State University Research N Foundation CoI: Dr. Howard E. Bond Space Telescope Science Institute N CoI: Dr. Mario Livio Space Telescope Science Institute N CoI: Dr. Edmund Nelan Space Telescope Science Institute N CoI: Dr. Warren R. Brown Smithsonian Institution Astrophysical N Observatory CoI: Dr. Margaret Geller Smithsonian Institution Astrophysical N Observatory CoI: Dr. Scott J. Kenyon Smithsonian Institution Astrophysical N Observatory CoI: Dr. Michael J. Kurtz Smithsonian Institution Astrophysical N Observatory 10824( 6) - 10/13/06 16:36 - [ 2] ------------------------------------------------------------------------------------ Abstract We propose to obtain high-resolution images of five hypervelocity stars in the Galactic halo in order to establish the first-epoch astrometric frame for them, as a part of a long-term program to measure precise proper motions. The origin of these recently discovered stars, all with positive radial velocities above 540 km/s, is consistent only with being ejected from the deep potential well of the massive black hole at the Galactic center. The deviations of their space motions from purely radial trajectories probe the departures from spherical symmetry of the Galactic potential, mainly due to the triaxiality of the dark-matter halo. Reconstructing the full three-dimensional space motion of the hypervelocity stars, through astrometric proper motions, provides a unique opportunity to measure the shape and orientation of the dark halo. The hypervelocity stars allow measurement of the potential up to 75 kpc from the center, independently of and at larger distances than are afforded by tidal streams of satellite galaxies such as the Sagittarius dSph galaxy. HVS3 may be associated with the LMC, rather then the Galactic center, and would therefore present a case for a supermassive black hole at the center of the LMC. We request one orbit with ACS/WFC for each of the five hypervelocity stars to establish their current positions relative to background galaxies. We will request a repeated observation of these stars in Cycle 17, which will conclusively measure the astrometric proper motions. ------------------------------------------------------------------------------------ Observations Description ------------------------ In this program we are obtaining first-epoch images of 5 hypervelocity stars. The aim is to measure their proper motions against the reference frame of background galaxies. Each target will be centered either in the middle of WFC1, or for the brightest targets we will reduce overheads by using the subraster WFC1-2K. The targets will be observed either in F814W or F850LP, which appear to be better filters than the F606W mentioned in the original proposal. The reason is that the crucial background galaxies will give a better S/N at longer wavelengths, according to the ACS ETC. For each target we will take the maximum number of exposures possible in one orbit, with appropriate dithering. Exposures are chosen for each target to be no more than 70% of saturation on the target star. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10824( 6) - 10/13/06 16:36 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ090745. STAR, BP, HALO RA=09H07M44.9900S +/- 0.1", J2000 V = 19.96+/-0.2 0+024507 DEC=+02D45'6.40" +/- 0.1" Reference Frame: ICRS 2 SDSSJ093320. STAR, BP, HALO RA=09H33M20.8800S +/- 0.1", J2000 V = 19.0+/-0.2 86+441705.4 DEC=+44D17'5.50" +/- 0.1" Reference Frame: ICRS 3 HE0437-5439 STAR, BP, HALO RA=04H38M12.7700S +/- 0.1", J2000 V = 16.2+/-0.2 DEC=-54D33'11.80" +/- 0.1" Reference Frame: ICRS 4 SDSSJ091301. STAR, BP, HALO RA=09H13M1.0000S +/- 0.1", J2000 V = 18.59+/-0.2 0+305120 DEC=+30D51'20.20" +/- 0.1" Reference Frame: ICRS 5 SDSSJ091759. STAR, BP, HALO RA=09H17M59.5500S +/- 0.1", J2000 V = 18.09+/-0.2 5+672238 DEC=+67D22'38.80" +/- 0.1" Reference Frame: ICRS 10824( 6) - 10/13/06 16:36 - [ 4] Visit: 01 Visit Priority: Visit Requirements: BEFORE 01-NOV-2006:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ090745 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 520 S .0+024507 see below ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ090745 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 520 S POS TARG 0.25073, 0.54151 .0+024507 see below ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ090745 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 520 S POS TARG 0.52487, 0.7861 .0+024507 see below ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSSJ090745 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 520 S POS TARG 0.7713, 0.33176 .0+024507 see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ090745.0+0245 1 ACS/WFC ACCUM WFC1 F814W none none none none 1 522.0 S 07 SDSSJ090745.0+0245 2 ACS/WFC ACCUM WFC1 F814W none none none none 1 522.0 S 07 SDSSJ090745.0+0245 3 ACS/WFC ACCUM WFC1 F814W none none none none 1 522.0 S 07 SDSSJ090745.0+0245 4 ACS/WFC ACCUM WFC1 F814W none none none none 1 522.0 S 07 10824( 6) - 10/13/06 16:36 - [ 5] Visit: 02 Visit Priority: Visit Requirements: BEFORE 20-OCT-2006:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ093320 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 520 S .86+441705. see below 4 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ093320 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 520 S POS TARG 0.25073, 0.54151 .86+441705. see below 4 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ093320 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 520 S POS TARG 0.52487, 0.7861 .86+441705. see below 4 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSSJ093320 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 520 S POS TARG 0.7713, 0.33176 .86+441705. see below 4 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ093320.86+441 1 ACS/WFC ACCUM WFC1 F814W none none none none 1 532.0 S 705.4 SDSSJ093320.86+441 2 ACS/WFC ACCUM WFC1 F814W none none none none 1 532.0 S 705.4 SDSSJ093320.86+441 3 ACS/WFC ACCUM WFC1 F814W none none none none 1 532.0 S 705.4 SDSSJ093320.86+441 4 ACS/WFC ACCUM WFC1 F814W none none none none 1 532.0 S 705.4 10824( 6) - 10/13/06 16:36 - [ 6] Visit: 03 Visit Priority: Visit Requirements: BEFORE 20-JUL-2006:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HE0437-5439 ACS/WFC ACCUM WFC1-2K F850LP CR-SPLIT=NO 1 255 S see below ------------------------------------------------------------------------------------------------------------------------------------ 2 HE0437-5439 ACS/WFC ACCUM WFC1-2K F850LP CR-SPLIT=NO 1 255 S POS TARG 0.29815, 0.0473 see below ------------------------------------------------------------------------------------------------------------------------------------ 3 HE0437-5439 ACS/WFC ACCUM WFC1-2K F850LP CR-SPLIT=NO 1 255 S POS TARG 0.6127, 0.04604 see below ------------------------------------------------------------------------------------------------------------------------------------ 4 HE0437-5439 ACS/WFC ACCUM WFC1-2K F850LP CR-SPLIT=NO 1 255 S POS TARG 0.16794, 0.53528 see below ------------------------------------------------------------------------------------------------------------------------------------ 5 HE0437-5439 ACS/WFC ACCUM WFC1-2K F850LP CR-SPLIT=NO 1 255 S POS TARG 0.48231, 0.53404 see below ------------------------------------------------------------------------------------------------------------------------------------ 6 HE0437-5439 ACS/WFC ACCUM WFC1-2K F850LP CR-SPLIT=NO 1 255 S POS TARG 0.78064, 0.58136 see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ HE0437-5439 1 ACS/WFC ACCUM WFC1-2K F850LP none none none none 1 257.0 S HE0437-5439 2 ACS/WFC ACCUM WFC1-2K F850LP none none none none 1 257.0 S HE0437-5439 3 ACS/WFC ACCUM WFC1-2K F850LP none none none none 1 257.0 S HE0437-5439 4 ACS/WFC ACCUM WFC1-2K F850LP none none none none 1 257.0 S HE0437-5439 5 ACS/WFC ACCUM WFC1-2K F850LP none none none none 1 257.0 S HE0437-5439 6 ACS/WFC ACCUM WFC1-2K F850LP none none none none 1 257.0 S 10824( 6) - 10/13/06 16:36 - [ 7] Visit: 04 Visit Priority: Visit Requirements: BEFORE 23-OCT-2006:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S POS TARG 0.26063, 0.53727 .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S POS TARG 0.5212, 1.07448 .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S POS TARG 0.77839, 0.81512 .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ 5 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S POS TARG 1.03448, 0.35651 .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ091301.0+3051 1 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 SDSSJ091301.0+3051 2 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 SDSSJ091301.0+3051 3 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 SDSSJ091301.0+3051 4 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 SDSSJ091301.0+3051 5 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 10824( 6) - 10/13/06 16:36 - [ 8] Visit: 05 Visit Priority: Visit Requirements: BEFORE 20-SEP-2006:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ091759 ACS/WFC ACCUM WFC1-2K F814W CR-SPLIT=NO 1 195 S .5+672238 see below ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ091759 ACS/WFC ACCUM WFC1-2K F814W CR-SPLIT=NO 1 195 S POS TARG 0.30527, 0.05137 .5+672238 see below ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ091759 ACS/WFC ACCUM WFC1-2K F814W CR-SPLIT=NO 1 195 S POS TARG 0.6104, 0.05299 .5+672238 see below ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSSJ091759 ACS/WFC ACCUM WFC1-2K F814W CR-SPLIT=NO 1 195 S POS TARG 0.1727, 0.5321 .5+672238 see below ------------------------------------------------------------------------------------------------------------------------------------ 5 SDSSJ091759 ACS/WFC ACCUM WFC1-2K F814W CR-SPLIT=NO 1 195 S POS TARG 0.47775, 0.56923 .5+672238 see below ------------------------------------------------------------------------------------------------------------------------------------ 6 SDSSJ091759 ACS/WFC ACCUM WFC1-2K F814W CR-SPLIT=NO 1 195 S POS TARG 0.7831, 0.59932 .5+672238 see below ------------------------------------------------------------------------------------------------------------------------------------ 7 SDSSJ091759 ACS/WFC ACCUM WFC1-2K F814W CR-SPLIT=NO 1 195 S POS TARG 0.93792, 0.33363 .5+672238 see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ091759.5+6722 1 ACS/WFC ACCUM WFC1-2K F814W none none none none 1 199.0 S 38 SDSSJ091759.5+6722 2 ACS/WFC ACCUM WFC1-2K F814W none none none none 1 199.0 S 38 SDSSJ091759.5+6722 3 ACS/WFC ACCUM WFC1-2K F814W none none none none 1 199.0 S 38 SDSSJ091759.5+6722 4 ACS/WFC ACCUM WFC1-2K F814W none none none none 1 199.0 S 38 SDSSJ091759.5+6722 5 ACS/WFC ACCUM WFC1-2K F814W none none none none 1 199.0 S 38 SDSSJ091759.5+6722 6 ACS/WFC ACCUM WFC1-2K F814W none none none none 1 199.0 S 38 SDSSJ091759.5+6722 7 ACS/WFC ACCUM WFC1-2K F814W none none none none 1 199.0 S 38 10824( 6) - 10/13/06 16:36 - [ 9] Visit: 54 Visit Priority: Visit Requirements: BEFORE 23-NOV-2006:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S POS TARG 0.26063, 0.53727 .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S POS TARG 0.5212, 1.07448 .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S POS TARG 0.77839, 0.81512 .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ 5 SDSSJ091301 ACS/WFC ACCUM WFC1 F814W CR-SPLIT=NO 1 390 S POS TARG 1.03448, 0.35651 .0+305120 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ091301.0+3051 1 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 SDSSJ091301.0+3051 2 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 SDSSJ091301.0+3051 3 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 SDSSJ091301.0+3051 4 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 SDSSJ091301.0+3051 5 ACS/WFC ACCUM WFC1 F814W none none none none 1 N/A 20 10824( 6) - 10/13/06 16:36 - [ 10] Summary Form for Proposal 10824 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC1 WFC1-2K ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 01-NOV-2006 00 00 00; POS TARG 0.25073, 0.54151; POS TARG 0.52487, 0.7861; POS TARG 0.7713, 0.33176; BEFORE 20-OCT-2006 00 00 00; BEFORE 20-JUL-2006 00 00 00; POS TARG 0.29815, 0.0473; POS TARG 0.6127, 0.04604; POS TARG 0.16794, 0.53528; POS TARG 0.48231, 0.53404; POS TARG 0.78064, 0.58136; BEFORE 23-OCT-2006 00 00 00; POS TARG 0.26063, 0.53727; POS TARG 0.5212, 1.07448; POS TARG 0.77839, 0.81512; POS TARG 1.03448, 0.35651; BEFORE 20-SEP-2006 00 00 00; POS TARG 0.30527, 0.05137; POS TARG 0.6104, 0.05299; POS TARG 0.1727, 0.5321; POS TARG 0.47775, 0.56923; POS TARG 0.7831, 0.59932; POS TARG 0.93792, 0.33363; BEFORE 23-NOV-2006 00 00 00; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W F850LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names SDSSJ090745.0+024507 SDSSJ093320.86+441705.4 HE0437-5439 SDSSJ091301.0+305120 SDSSJ091759.5+672238 ------------------------------------------------------------------------------------------------------------------------------------