17243( 4) - 27-Sep-2023 16:52:16 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17243 Version: 4 Check-in Time: 27-Sep-2023 16:52:16 STScI Edit Number: 1 Title DECALS J0542-2125: The Dynamical State of an Extraordinary Cluster Merger at z = 0.61 ------------------------------------------------------------------------------------ Type Cycle GO 30 ------------------------------------------------------------------------------------ Investigators Contact? PI: Ms. Kate Napier University of Michigan Y CoI: Prof. Keren Sharon University of Michigan N CoI: Prof. Michael D. Gladders University of Chicago N CoI: Dr. Matthew Bayliss University of Cincinnati Main Campus N CoI: Dr. Gourav Khullar University of Pittsburgh N CoI: Dr. Haakon Dahle University of Oslo N CoI: Dr. Jane R. Rigby NASA Goddard Space Flight Center N CoI: Mr. Michael Martinez University of Wisconsin - Madison N ------------------------------------------------------------------------------------ Abstract Merging galaxy clusters are rare laboratories to test the nature of dark matter and hierarchical assembly. We propose Chandra observation of DECALS J0542-2125, a candidate cluster merger at z=0.61. Two galaxy clusters of comparable mass are separated by < 500 km/s and 1 Mpc in projection. Additionally, one cluster gravitationally lenses a z=1.84 quasar, the largest-separation lensed quasar known. The proposed Chandra data will provide the necessary resolution to determine the morphology of the X-ray emitting gas and definitely determine the system's dynamical state. Joint Hubble Space Telescope observations will provide the necessary constraints for a robust lens model. Taken together, this program will map the distribution of dark matter, X-ray gas, and stars in DECALS J0542-2125. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program observes two strong lensing cores separated by ~150 arcsec, less than the ACS field of view. The 5-orbit program includes a combination of ACS and WFC3 observations across five visits. Each visit contains only a single orbit to maximize schedulability - particularly important because 4 of the 5 orbits have roll angle constraints as detailed in the Phase I proposal. Overall, the program aims to image both cores in F606W and F814W using ACS (single pointing with a particular small range of angles), both cores in F105W and F160W using WFC3-IR (separate pointings), and the primary lensing core (involving a wide-separation lensed quasar) for ~1.5 orbits in F390W. Visit 1 uses the ACS F606W filter. It employs an orientation constraint of 290-315 degrees to fit both lensing cores on the instrument at once. This visit includes 2068 s of F606W imaging. Visit 2 uses the ACS F814W filter. Likewise, it employs the same orientation constraint as Visit 1 to simultaneously image both lensing cores. This visit includes 2068 s of F814W imaging. 17243( 4) - 27-Sep-2023 16:52:16 - [ 2] Visit 3 uses the WFC3-IR F105W and WFC3-IR F160W filters to image the secondary lensing core. This visit includes 1011 s of F105W imaging and 1211 s of F160W imaging. Visit 4 uses the WFC3-IR F160W, F105W filters and the UVIS-F390W filter to image the primary lensing core, in 2 orbits. An orientation constraint of 25-65 degrees is employed to optimally sample the primary lensing core and region between the two lensing cores. The primary impact of reduced gyro operations for this program is the effect on the roll angle constraints, and the commensurate reductions in schedulability. Visits 1-2 have roll angle constraints so both lensing cores land on the instrument at once. If this was no longer schedulable, two separate pointings may have to be used to cover both cores. Visits 3 has a roll angle constraints to optimally sample the primary lensing core and the region between the two lensing cores. These roll angle constraints could be relaxed in the event of reduced gyro operations by prioritizing imaging of the primary lensing core. Finally, Visit 4 has no roll angle constraint and therefore would not be very affected by reduced gyro operations. ------------------------------------------------------------------------------------ 17243( 4) - 27-Sep-2023 16:52:16 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 DECALSJ0542- CLUSTER OF GALAXIES, RA=05H42M51.6240S, J2000 V = 21 +/- 0.1 2125-1 GRAVITATIONAL LENS, DEC=-21D25'42.53" RICH CLUSTER, SUPERCLUSTER Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 2 DECALSJ0542- CLUSTER OF GALAXIES, RA=05H42M56.7000S, J2000 V = 21 +/- 0.1 2125-2 GRAVITATIONAL LENS, DEC=-21D25'44.00" RICH CLUSTER, SUPERCLUSTER Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 3 DECALSJ0542- CLUSTER OF GALAXIES, RA=05H42M46.9852S, J2000 V = 21 +/- 0.1 2125-3 GRAVITATIONAL LENS, DEC=-21D25'54.30" RICH CLUSTER, SUPERCLUSTER Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 17243( 4) - 27-Sep-2023 16:52:16 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 3.034 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.29 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.572 Line_Spacing 0.365 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 5 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 1.75085 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 17243( 4) - 27-Sep-2023 16:52:16 - [ 5] Visit: 01 (ACS F606W) Visit Requirements: ORIENT 290D TO 315 D On Hold Comments: Additional Comments: both lensing cores 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 DECALSJ0542 ACS/WFC ACCUM WFC F606W 1 530 S PATTERN 2 1 -2125-1 see below (2068 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 | ------------------------------------------------------------------------------------------------------------------------------------ DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F606W 1 none none none 1 517.0 S DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F606W 2 none none none 1 517.0 S DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F606W 3 none none none 1 517.0 S DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F606W 4 none none none 1 517.0 S 17243( 4) - 27-Sep-2023 16:52:16 - [ 6] Visit: 02 (ACS F814W) Visit Requirements: ORIENT 290D TO 315 D On Hold Comments: Additional Comments: both lensing cores 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 DECALSJ0542 ACS/WFC ACCUM WFC F814W 1 530 S PATTERN 2 1 -2125-1 see below (2068 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 | ------------------------------------------------------------------------------------------------------------------------------------ DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F814W 1 none none none 1 517.0 S DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F814W 2 none none none 1 517.0 S DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F814W 3 none none none 1 517.0 S DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F814W 4 none none none 1 517.0 S 17243( 4) - 27-Sep-2023 16:52:16 - [ 7] Visit: 05 (WFC3-IR F1053+F160W) Visit Requirements: On Hold Comments: Additional Comments: secondary lensing core 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 DECALSJ0542 WFC3/IR MULTIAC IR F160W NSAMP=7, SAMP-SEQ=SPARS50 1 DEF -2125-3 CUM (302.935 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 DECALSJ0542 WFC3/IR MULTIAC IR F160W NSAMP=7, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.542, 0.182 -2125-3 CUM (302.935 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 DECALSJ0542 WFC3/IR MULTIAC IR F105W NSAMP=6, SAMP-SEQ=SPARS50 1 DEF PATTERN 4 3 -2125-3 CUM (1011.738 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 DECALSJ0542 WFC3/IR MULTIAC IR F160W NSAMP=7, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.339, 0.485 -2125-3 CUM (302.935 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 DECALSJ0542 WFC3/IR MULTIAC IR F160W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG -0.203, 0.303 -2125-3 CUM (352.935 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 | ------------------------------------------------------------------------------------------------------------------------------------ DECALSJ0542-2125-3 1 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM DECALSJ0542-2125-3 2 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM DECALSJ0542-2125-3 3 WFC3/IR MULTIAC IR F105W 1 none none none 1 N/A CUM DECALSJ0542-2125-3 3 WFC3/IR MULTIAC IR F105W 2 none none none 1 N/A CUM DECALSJ0542-2125-3 3 WFC3/IR MULTIAC IR F105W 3 none none none 1 N/A CUM DECALSJ0542-2125-3 3 WFC3/IR MULTIAC IR F105W 4 none none none 1 N/A CUM DECALSJ0542-2125-3 4 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM DECALSJ0542-2125-3 5 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM 17243( 4) - 27-Sep-2023 16:52:16 - [ 8] Visit: 06 (WFC3-IR F105W F160W UVIS F390W) Visit Requirements: ORIENT 25D TO 65 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 DECALSJ0542 WFC3/IR MULTIAC IR F160W NSAMP=4, SAMP-SEQ=SPARS50 1 DEF PATTERN 4 1 -2125-2 CUM (611.735 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 DECALSJ0542 WFC3/IR MULTIAC IR F105W NSAMP=8, SAMP-SEQ=SPARS25 1 DEF PATTERN 4 2 -2125-2 CUM (711.744 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 DECALSJ0542 WFC3/UVI ACCUM UVIS2 F390W FLASH=10 1 829 S PATTERN 5 3 -2125-2 S (3316 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 | ------------------------------------------------------------------------------------------------------------------------------------ DECALSJ0542-2125-2 1 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A CUM DECALSJ0542-2125-2 1 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A CUM DECALSJ0542-2125-2 1 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A CUM DECALSJ0542-2125-2 1 WFC3/IR MULTIAC IR F160W 4 none none none 1 N/A CUM DECALSJ0542-2125-2 2 WFC3/IR MULTIAC IR F105W 1 none none none 1 N/A CUM DECALSJ0542-2125-2 2 WFC3/IR MULTIAC IR F105W 2 none none none 1 N/A CUM DECALSJ0542-2125-2 2 WFC3/IR MULTIAC IR F105W 3 none none none 1 N/A CUM DECALSJ0542-2125-2 2 WFC3/IR MULTIAC IR F105W 4 none none none 1 N/A CUM DECALSJ0542-2125-2 3 WFC3/UVI ACCUM UVIS2 F390W 1 none none none 1 N/A S DECALSJ0542-2125-2 3 WFC3/UVI ACCUM UVIS2 F390W 2 none none none 2 N/A S DECALSJ0542-2125-2 3 WFC3/UVI ACCUM UVIS2 F390W 3 none none none 2 N/A S DECALSJ0542-2125-2 3 WFC3/UVI ACCUM UVIS2 F390W 4 none none none 2 N/A S 17243( 4) - 27-Sep-2023 16:52:16 - [ 9] Visit: 51 (ACS F606W) Visit Requirements: ORIENT 290D TO 315 D On Hold Comments: Additional Comments: both lensing cores HOPR repeat of visit 1 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 DECALSJ0542 ACS/WFC ACCUM WFC F606W 1 530 S PATTERN 2 1 -2125-1 see below (2068 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 | ------------------------------------------------------------------------------------------------------------------------------------ DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F606W 1 none none none 1 517.0 S DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F606W 2 none none none 1 517.0 S DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F606W 3 none none none 1 517.0 S DECALSJ0542-2125-1 1 ACS/WFC ACCUM WFC F606W 4 none none none 1 517.0 S 17243( 4) - 27-Sep-2023 16:52:16 - [ 10] Summary Form for Proposal 17243 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, UVIS2, WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=10, NSAMP=4, NSAMP=6, NSAMP=7, NSAMP=8, SAMP-SEQ=SPARS25, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 25D TO 65 D, ORIENT 290D TO 315 D, PATTERN 2 1, PATTERN 4 1, PATTERN 4 2, PATTERN 4 3, PATTERN 5 3, POS TARG -0.203, 0.303, POS TARG 0.339, 0.485, POS TARG 0.542, 0.182 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F105W, F160W, F390W, F606W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names DECALSJ0542-2125-1, DECALSJ0542-2125-2, DECALSJ0542-2125-3 ------------------------------------------------------------------------------------------------------------------------------------