10200( 6) - 05/14/04 07:09 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10200 Version: 6 Check-in Date: 14-May-2004 11:08:08 1.Proposal Title: Dark Matter Constraints from the Merging Cluster 1E0657-56 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 13 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Christine Jones Smithsonian Institution Astrophysical Observatory CoI: Dr. William R. Forman Smithsonian Institution Astrophysical N Observatory CoI: Dr. Anthony H. Gonzalez University of Florida N CoI: Dr. Douglas Clowe University of Arizona N CoI: Dr. Maxim Markevitch Smithsonian Institution Astrophysical N Observatory ------------------------------------------------------------------------------------ 6. Abstract We propose five orbits of ACS Wide Field Camera observations (three orbits with F814W, one with F606W, and one with F435W) to investigate the unique, high velocity merging cluster 1E0657-56(z=0.296). Coupling the ACS images with deep Chandra observations and ground-based imaging will allow us to compare maps of the intracluster medium, the dark matter, and the galaxies from which we can directly estimate the self-interaction cross-section of dark matter, the dominant mass component in clusters and the Universe. These observations, combined with hydrodynamic simulations, will either rule out the range of cross-sections proposed to alleviate problems with collisionless dark matter or unambiguously detect and measure the self-interaction cross-section. A secondary objective is to quantify the impact of a supersonic merger on star formation and the morphological evolution of cluster galaxies. The geometry of 1E0657-56 (with the merger nearly in the plane of the sky) coupled with the subcluster velocity (4500 km/s) accurately constrains the timescale of the merger. In particular since the subcluster traversed the dense core of the main cluster only 0.15 Gyr ago, star formation induced by the core passage will be clearly visible. ------------------------------------------------------------------------------------ 10200( 6) - 05/14/04 07:09 - [ 2] Observations Description ------------------------ To generate an accurate weak lensing mass map and investigate the effects of a supersonic merger on star formation in the cluster 1E0657-56 requires one pointing. We request 3 orbits in F814W, 1 orbit in F606W and 1 in F435W. Three filters are necessary to minimize confusion in the subcluster core and distinguish faint cluster galaxies from background sources. With the F606W and F814W colors, we can effectively remove red-sequence galaxies, while with the addition of the F435W blue filter, we will also be able to reject cluster spirals from the background galaxy catalog and probe recent star formation. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10200( 6) - 05/14/04 07:09 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GAL-CLUS- CLUSTER OF GALAXIES, RA=06H58M19.0S +/- 0.5", DEC=- J2000 Z = V = 21.0+/-1.0 065819- RICH CLUSTER 55D56'35.0" +/- 2.0" 0.0296 555635 Coordinate Source: Other_Source: Other (Chandra image) Comments: PI submitted with alternate name of 1E0657-56. Software viewed this as being scientific notation and crashed. Value removed for now by PC. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 0.0 0.0 0.0 2 GAL-CLUS- CLUSTER OF GALAXIES, RA=06H58M32.0S +/- 0.5", DEC=- J2000 Z = V = 21.0+/-1.0 065832- RICH CLUSTER 55D57'0.00" +/- 2.0" 0.0296 555700 Coordinate Source: Other_Source: Other (Chandra image) Comments: PI submitted with alternate name of 1E0657-56. Software viewed this as being scientific notation and crashed. Value removed for now by PC. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000.0 0.0 0.0 0.0 10200( 6) - 05/14/04 07:09 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 3.011 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.28 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type LINE ACS-WFC-DITHER-LINE Pattern_Purpose DITHER DITHER Number_Of_Points 2 2 Point_Spacing 3.011 1.265 Line_Spacing Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 85.28 85.28 Angle_Between_Sides Center_Pattern YES NO ------------------------------------------------------------------------------------------------------------------------------------ 10200( 6) - 05/14/04 07:09 - [ 5] Visit: 01 Visit Priority: Visit Requirements: 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 GAL-CLUS-06 ACS/WFC ACCUM WFC F606W CR-SPLIT=NO 1 584 S PATTERN 2 1 5819-555635 ------------------------------------------------------------------------------------------------------------------------------------ 2 GAL-CLUS-06 ACS/WFC ACCUM WFC F814W CR-SPLIT=NO 2 618 S PATTERN 2 2 5819-555635 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 01 1 1 1 none none 1 tbd 01 1 1 2 none none 1 tbd 01 1 2 1 none none 1 tbd 01 1 2 2 none none 1 tbd 01 2 1 1 1 none 2 tbd 01 2 1 1 2 none 2 tbd 01 2 1 2 1 none 2 tbd 01 2 1 2 2 none 2 tbd 01 2 2 1 1 none 3 tbd 01 2 2 1 2 none 3 tbd 01 2 2 2 1 none 3 tbd 01 2 2 2 2 none 3 tbd 10200( 6) - 05/14/04 07:09 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT -15.0D TO 15.0D FROM 01 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 GAL-CLUS-06 ACS/WFC ACCUM WFC F606W CR-SPLIT=NO 1 584 S PATTERN 2 1 5832-555700 ------------------------------------------------------------------------------------------------------------------------------------ 2 GAL-CLUS-06 ACS/WFC ACCUM WFC F435W CR-SPLIT=NO 1 605 S PATTERN 2 2 5819-555635 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 02 1 1 1 none none 1 tbd 02 1 1 2 none none 1 tbd 02 1 2 1 none none 1 tbd 02 1 2 2 none none 1 tbd 02 2 1 1 none none 2 tbd 02 2 1 2 none none 2 tbd 02 2 2 1 none none 2 tbd 02 2 2 2 none none 2 tbd 10200( 6) - 05/14/04 07:09 - [ 7] Summary Form for Proposal 10200 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 2 1 PATTERN 2 2 ORIENT -15.0D TO 15.0D FROM 01 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F606W F814W F435W ------------------------------------------------------------------------------------------------------------------------------------ Target Names GAL-CLUS-065819-555635 GAL-CLUS-065832-555700 ------------------------------------------------------------------------------------------------------------------------------------