17519( 9) - 03-Jun-2025 19:59:21 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17519 Version: 9 Check-in Time: 03-Jun-2025 19:59:21 STScI Edit Number: 2 Title Chasing the tail: measuring a proper motion of the Coma cluster dwarf ram-pressure-stripped galaxy GMP2640 with its extraordinary star cluster population. ------------------------------------------------------------------------------------ Type Cycle GO 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Igor Chilingarian Smithsonian Institution Astrophysical Y Observatory CoI: Dr. Anton V. Afanasiev Observatoire de Paris N CoI: Dr. Kirill Grishin Universite Paris Diderot (Paris 7) N CoI: Dr. Ivan Katkov New York University Abu Dhabi N ------------------------------------------------------------------------------------ Abstract GMP2640 is the most luminous diffuse post-starburst galaxy in the Coma cluster (D=99Mpc) identified using data mining. Despite relatively low stellar mass (2.4*10^9 MSun), it hosts a strikingly large population of 450+ massive intermediate-age star clusters detected in an archival HST image in its disk and hundreds of additional clusters in its spectacular 270kpc-long ram-pressure-blown tail. Measuring age gradient of clusters along the tail opens a unique opportunity to measure a velocity of GMP2640 in the plane of the sky, i.e. its proper motion at the striking distance of 100Mpc. We propose to collect high-resolution HST images of GMP2640 and its tail using WFC3 in prime orbits and ACS/WFC in coordinated parallel fields. We will detect star cluster populations and measure their ages, metallicities, hence mass and luminosity functions, and assess the plausibility of the formation of central star clusters in a dEs via mergers of in-situ formed star clusters. Our project will address the question of rich star cluster systems in low-mass galaxies as well as the question of dE/UDG formation via ram pressure stripping in galaxy clusters. ------------------------------------------------------------------------------------ Observations Description ------------------------ Here we propose to obtain high-resolution NUV and optical images of the diffuse post-starburst galaxy GMP 2640 and its spectacular tail with WFC3/UVIS using a special combination of filters to disentangle age and metallicity effects in stellar populations (and Advanced Camera for Surveys in the coordinated parallel mode for the older part of the tail). The selected filters are F200LP, F350LP, and F600LP filters for WFC3-UVIS scheduled for the 6 primary orbits (3 orbits per field; 1 orbit per filter). (i) the F200LP-F350LP difference image provides the deepest broad-band near-UV imaging available at the HST, which is required to precisely age young and intermediate-age star clusters and by using UV stellar continuum from B and A stars (GMP~2640 has a strong GALEX detection); (ii) F600LP will be the primary filter for the 2D light profile decomposition of the main galaxy spheroid; the F350_600LP-F650LP color will be used to estimate stellar population gradients. This filter combination will be crucial to measure star cluster ages and metallicities. We will use coordinated parallel observations of the outer part of the RPS tail of GMP 2640 with ACS/WFC using optical colors (2 orbits in F475W and 1 orbit in F814W for each 17519( 9) - 03-Jun-2025 19:59:21 - [ 2] pointing). The main goal of the parallel observations is the to collect deep optical images of the filaments of the tail, which are not resolved into clusters in the ground-based Subaru HyperSuprimeCam (120 - 250 kpc from the center of GMP 2640). If we detect fainter and older star clusters, this will become an important step towards understanding the unbound star cluster population and its contribution to the intracluster light in Coma. For this reason, we have a position angle constraint of 110+- 10 deg (a slight change in the angle can be compensated by shifting the center of the field) limiting the scheduling to Jun--Aug. ------------------------------------------------------------------------------------ 17519( 9) - 03-Jun-2025 19:59:21 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GMP2640 GALAXY, DWARF RA=13H00M24.3232S, J2000 V = 15.9 ELLIPTICAL DEC=+27D31'43.43" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640-TAIL ISM, TIDAL TAIL RA=13H00M22.7926S, J2000 V = 27.0 DEC=+27D34'21.38" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 17519( 9) - 03-Jun-2025 19:59:21 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-GAP-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 3.6 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.759 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 17519( 9) - 03-Jun-2025 19:59:21 - [ 5] Visit: 01 (GMP2640) Visit Requirements: ORIENT 130D TO 143 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 GMP2640 WFC3/UVI ACCUM UVIS F200LP 1 1275 S PATTERN 1 1-2; PAR 2 S see below WITH 1 (2410 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640 ACS/WFC ACCUM WFC F814W 2 525 S see below (1992 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 | ------------------------------------------------------------------------------------------------------------------------------------ GMP2640 1 WFC3/UVI ACCUM UVIS F200LP 1 none none none 1 1205.0 S S GMP2640 1 WFC3/UVI ACCUM UVIS F200LP 2 none none none 1 1205.0 S S GMP2640 2 ACS/WFC ACCUM WFC F814W 1 none 1 none 1 503.0 S GMP2640 2 ACS/WFC ACCUM WFC F814W 1 none 2 none 1 503.0 S GMP2640 2 ACS/WFC ACCUM WFC F814W 2 none 1 none 1 493.0 S GMP2640 2 ACS/WFC ACCUM WFC F814W 2 none 2 none 1 493.0 S 17519( 9) - 03-Jun-2025 19:59:21 - [ 6] Visit: 02 (GMP2640) Visit Requirements: SAME ORIENT AS 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GMP2640 WFC3/UVI ACCUM UVIS F350LP 1 1275 S PATTERN 1 1-2; PAR 2 S see below WITH 1 (2410 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640 ACS/WFC ACCUM WFC F475W 2 525 S see below (1992 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 | ------------------------------------------------------------------------------------------------------------------------------------ GMP2640 1 WFC3/UVI ACCUM UVIS F350LP 1 none none none 1 1205.0 S S GMP2640 1 WFC3/UVI ACCUM UVIS F350LP 2 none none none 1 1205.0 S S GMP2640 2 ACS/WFC ACCUM WFC F475W 1 none 1 none 1 503.0 S GMP2640 2 ACS/WFC ACCUM WFC F475W 1 none 2 none 1 503.0 S GMP2640 2 ACS/WFC ACCUM WFC F475W 2 none 1 none 1 493.0 S GMP2640 2 ACS/WFC ACCUM WFC F475W 2 none 2 none 1 493.0 S 17519( 9) - 03-Jun-2025 19:59:21 - [ 7] Visit: 03 (GMP2640) Visit Requirements: SAME ORIENT AS 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GMP2640 WFC3/UVI ACCUM UVIS F600LP 1 1275 S PATTERN 1 1-2; PAR 2 S see below WITH 1 (2410 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640 ACS/WFC ACCUM WFC F475W 2 525 S see below (1992 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 | ------------------------------------------------------------------------------------------------------------------------------------ GMP2640 1 WFC3/UVI ACCUM UVIS F600LP 1 none none none 1 1205.0 S S GMP2640 1 WFC3/UVI ACCUM UVIS F600LP 2 none none none 1 1205.0 S S GMP2640 2 ACS/WFC ACCUM WFC F475W 1 none 1 none 1 503.0 S GMP2640 2 ACS/WFC ACCUM WFC F475W 1 none 2 none 1 503.0 S GMP2640 2 ACS/WFC ACCUM WFC F475W 2 none 1 none 1 493.0 S GMP2640 2 ACS/WFC ACCUM WFC F475W 2 none 2 none 1 493.0 S 17519( 9) - 03-Jun-2025 19:59:21 - [ 8] Visit: 04 (GMP2640-TAIL) Visit Requirements: ORIENT 130D TO 143 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 GMP2640-TAI WFC3/UVI ACCUM UVIS F200LP 1 1275 S PATTERN 1 1-2; PAR 2 L S see below WITH 1 (2410 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640-TAI ACS/WFC ACCUM WFC F814W 2 525 S L see below (1992 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 | ------------------------------------------------------------------------------------------------------------------------------------ GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F200LP 1 none none none 1 1205.0 S S GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F200LP 2 none none none 1 1205.0 S S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F814W 1 none 1 none 1 503.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F814W 1 none 2 none 1 503.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F814W 2 none 1 none 1 493.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F814W 2 none 2 none 1 493.0 S 17519( 9) - 03-Jun-2025 19:59:21 - [ 9] Visit: 05 (GMP2640-TAIL) Visit Requirements: SAME ORIENT AS 04 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 GMP2640-TAI WFC3/UVI ACCUM UVIS F350LP 1 1275 S PATTERN 1 1-2; PAR 2 L S see below WITH 1 (2406 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640-TAI ACS/WFC ACCUM WFC F475W 2 525 S L see below (1986 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 | ------------------------------------------------------------------------------------------------------------------------------------ GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F350LP 1 none none none 1 1203.0 S S GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F350LP 2 none none none 1 1203.0 S S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 1 none 1 none 1 501.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 1 none 2 none 1 501.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 2 none 1 none 1 492.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 2 none 2 none 1 492.0 S 17519( 9) - 03-Jun-2025 19:59:21 - [ 10] Visit: 06 (GMP2640-TAIL) Visit Requirements: SAME ORIENT AS 04 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 GMP2640-TAI WFC3/UVI ACCUM UVIS F600LP 1 1275 S PATTERN 1 1-2; PAR 2 L S see below WITH 1 (2410 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640-TAI ACS/WFC ACCUM WFC F475W 2 525 S L see below (1992 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 | ------------------------------------------------------------------------------------------------------------------------------------ GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F600LP 1 none none none 1 1205.0 S S GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F600LP 2 none none none 1 1205.0 S S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 1 none 1 none 1 503.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 1 none 2 none 1 503.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 2 none 1 none 1 493.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 2 none 2 none 1 493.0 S 17519( 9) - 03-Jun-2025 19:59:21 - [ 11] Visit: 07 (visit 04 repeat) 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GMP2640-TAI WFC3/UVI ACCUM UVIS F200LP 1 1275 S PATTERN 1 1-2; PAR 2 L S see below WITH 1 (2410 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640-TAI ACS/WFC ACCUM WFC F814W 2 525 S L see below (1992 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 | ------------------------------------------------------------------------------------------------------------------------------------ GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F200LP 1 none none none 1 1205.0 S S GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F200LP 2 none none none 1 1205.0 S S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F814W 1 none 1 none 1 503.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F814W 1 none 2 none 1 503.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F814W 2 none 1 none 1 493.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F814W 2 none 2 none 1 493.0 S 17519( 9) - 03-Jun-2025 19:59:21 - [ 12] Visit: 08 (visit 05 repeat) 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GMP2640-TAI WFC3/UVI ACCUM UVIS F350LP 1 1275 S PATTERN 1 1-2; PAR 2 L S see below WITH 1 (2406 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640-TAI ACS/WFC ACCUM WFC F475W 2 525 S L see below (1986 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 | ------------------------------------------------------------------------------------------------------------------------------------ GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F350LP 1 none none none 1 1203.0 S S GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F350LP 2 none none none 1 1203.0 S S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 1 none 1 none 1 501.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 1 none 2 none 1 501.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 2 none 1 none 1 492.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 2 none 2 none 1 492.0 S 17519( 9) - 03-Jun-2025 19:59:21 - [ 13] Visit: 09 (Visit 06 repeat) 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GMP2640-TAI WFC3/UVI ACCUM UVIS F600LP 1 1275 S PATTERN 1 1-2; PAR 2 L S see below WITH 1 (2410 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GMP2640-TAI ACS/WFC ACCUM WFC F475W 2 525 S L see below (1992 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 | ------------------------------------------------------------------------------------------------------------------------------------ GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F600LP 1 none none none 1 1205.0 S S GMP2640-TAIL 1 WFC3/UVI ACCUM UVIS F600LP 2 none none none 1 1205.0 S S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 1 none 1 none 1 503.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 1 none 2 none 1 503.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 2 none 1 none 1 493.0 S GMP2640-TAIL 2 ACS/WFC ACCUM WFC F475W 2 none 2 none 1 493.0 S 17519( 9) - 03-Jun-2025 19:59:21 - [ 14] Summary Form for Proposal 17519 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS, WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 130D TO 143 D, PAR 2 WITH 1, PATTERN 1 1-2, SAME ORIENT AS 01, SAME ORIENT AS 04 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F200LP, F350LP, F475W, F600LP, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names GMP2640, GMP2640-TAIL ------------------------------------------------------------------------------------------------------------------------------------