13514( 2) - 02-Oct-2013 17:33:49 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13514 Version: 2 Check-in Time: 02-Oct-2013 17:33:49 STScI Edit Number: 0 Title Snapshots In The History Of Dissociative Major Mergers ------------------------------------------------------------------------------------ Type Cycle GO 21 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Florian Pacaud Universitaet Bonn, Inst fur Astrophysik Y und Extraterrestris CoI: Dr. Matthias Klein Universitaet Bonn, Inst fur Astrophysik N und Extraterrestris CoI: Dr. Kaustuv Basu Universitaet Bonn, Inst fur Astrophysik N und Extraterrestris CoI: Dr. Martin Sommer Universitaet Bonn, Inst fur Astrophysik N und Extraterrestris CoI: Dr. Holger Israel Universitat Bonn, Argelander Institute for N Astronomy CoI: Prof. Frank Bertoldi Universitat Bonn, Argelander Institute for N Astronomy CoI: Dr. Amy Bender McGill University N CoI: Dr. Matt Dobbs McGill University N CoI: Dr. Nils Halverson University of Colorado at Boulder N CoI: Prof. William Holzapfel University of California - Berkeley N CoI: Dr. Cathy Horellou Onsala Space Observatory N CoI: Dr. James Kennedy McGill University N CoI: Dr. Adrian Lee University of California - Berkeley N CoI: Dr. Thomas Reiprich Universitat Bonn, Argelander Institute for N Astronomy CoI: Prof. Peter Schneider Universitat Bonn, Argelander Institute for N Astronomy CoI: Dr. Uli Klein Universitaet Bonn, Inst fur Astrophysik N und Extraterrestris ------------------------------------------------------------------------------------ Abstract We propose joint Chandra/HST observations of two z=0.3 cluster mergers presenting offsets between the gas and dark matter distribution. Both were discovered within the follow-up program of the APEX-SZ experiment. The first one shows a bullet structure with a probable bow shock. The new data will permit an accurate joint X-ray, Sunyaev-Zel'dovich effect and lensing analysis to characterize both the thermodynamical state of its intracluster gas and the distribution of dark matter around it. The second cluster lacks good X-ray data and we request a short Chandra observations to confirm the gas distribution. Combined with three similar systems from the APEX-SZ sample, we aim at reconstructing obsevationally the time sequence of dissociative mergers. ------------------------------------------------------------------------------------ Observations Description ------------------------ We perform deep ACS/WFC observations on the merging cluster AS0295 for a high 13514( 2) - 02-Oct-2013 17:33:49 - [ 2] resolution mass map based on gravitational lensing. The cluster will be observed in F435W (1 Orbit), F606W (1 Orbit) and F814W (2 Orbits). The filter F814W will be primarily used for the shape measurements needed for the weak lensing analysis. Shape measurements will also applied to the F606W observations for diagnostics and to shrink measurement errors. The combination of all three filters will allow the identification of red and blue cluster members. Further, the color informations are used to identify multiply imaged galaxies in the strong lensing regime and to constrain the redshift range of these sources. To fill the gap between the ACS/WFC chips, we use a linear pattern with four exposures. The allowed orientation angle of the observations is restricted in order to optimize the FoV along the merger axis and to avoid a bright star ( V=11 mag) to enter the field of view of ACS/WFC. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 13514( 2) - 02-Oct-2013 17:33:49 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 ACO-S-295 CLUSTER OF GALAXIES, RA=02H45M29.7870S, J2000 Z = 0.3 V = 20 +/- 1 GRAVITATIONAL LENS, DEC=-53D02'24.55" RICH CLUSTER Reference Frame: ICRS Comments: The target position is slightly shifted with respect to the SIMBAD coordinates to center the merginging system within the FoV of ACS/WFC. ------------------------------------------------------------------------------------------------------------------------------------ 13514( 2) - 02-Oct-2013 17:33:49 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 3.011 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.28 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 13514( 2) - 02-Oct-2013 17:33:49 - [ 5] Visit: 01 Visit Requirements: ORIENT 330D TO 30 D; ORIENT 50D TO 111 D 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 ACO-S-295 ACS/WFC ACCUM WFCENTER F435W 1 480 S LOW-SKY; PATTERN 2 1 (1920 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACO-S-295 ACS/WFC ACCUM WFCENTER F606W 1 484 S LOW-SKY; PATTERN 2 2 (1936 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACO-S-295 ACS/WFC ACCUM WFCENTER F814W 1 486 S LOW-SKY; PATTERN 2 3 (1944 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACO-S-295 ACS/WFC ACCUM WFCENTER F814W 1 500 S LOW-SKY; PATTERN 2 4 (2000 S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACO-S-295 1 ACS/WFC ACCUM WFCENTER F435W 1 none none none 1 N/A ACO-S-295 1 ACS/WFC ACCUM WFCENTER F435W 2 none none none 1 N/A ACO-S-295 1 ACS/WFC ACCUM WFCENTER F435W 3 none none none 1 N/A ACO-S-295 1 ACS/WFC ACCUM WFCENTER F435W 4 none none none 1 N/A ACO-S-295 2 ACS/WFC ACCUM WFCENTER F606W 1 none none none 2 N/A ACO-S-295 2 ACS/WFC ACCUM WFCENTER F606W 2 none none none 2 N/A ACO-S-295 2 ACS/WFC ACCUM WFCENTER F606W 3 none none none 2 N/A ACO-S-295 2 ACS/WFC ACCUM WFCENTER F606W 4 none none none 2 N/A ACO-S-295 3 ACS/WFC ACCUM WFCENTER F814W 1 none none none 3 N/A ACO-S-295 3 ACS/WFC ACCUM WFCENTER F814W 2 none none none 3 N/A ACO-S-295 3 ACS/WFC ACCUM WFCENTER F814W 3 none none none 3 N/A ACO-S-295 3 ACS/WFC ACCUM WFCENTER F814W 4 none none none 3 N/A ACO-S-295 4 ACS/WFC ACCUM WFCENTER F814W 1 none none none 4 N/A ACO-S-295 4 ACS/WFC ACCUM WFCENTER F814W 2 none none none 4 N/A ACO-S-295 4 ACS/WFC ACCUM WFCENTER F814W 3 none none none 4 N/A ACO-S-295 4 ACS/WFC ACCUM WFCENTER F814W 4 none none none 4 N/A 13514( 2) - 02-Oct-2013 17:33:49 - [ 6] Summary Form for Proposal 13514 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFCENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements LOW-SKY, ORIENT 330D TO 30 D, ORIENT 50D TO 111 D, PATTERN 2 1, PATTERN 2 2, PATTERN 2 3, PATTERN 2 4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F435W, F606W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names ACO-S-295 ------------------------------------------------------------------------------------------------------------------------------------