15968( 2) - 09-Jul-2019 17:22:15 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15968 Version: 2 Check-in Time: 09-Jul-2019 17:22:15 STScI Edit Number: 0 Title Paths to quiescence: gaseous feeding, morphology and star-formation histories of galaxies from the HST+MUSE Ultra Deep Field ------------------------------------------------------------------------------------ Type Cycle GO 27 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Matteo Fossati Durham Univ. Y CoI: Prof. Michele Fumagalli Durham Univ. N CoI: Dr. Marc Rafelski Space Telescope Science Institute Y CoI: Dr. Rich Bielby Durham Univ. N CoI: Dr. Valentina D'Odorico INAF, Osservatorio Astronomico di Trieste N CoI: Dr. Pratika Dayal Kapteyn Astronomical Institute N CoI: Vicente Estrada-Carpenter Texas A & M University N CoI: Dr. Emma Lofthouse Durham Univ. N CoI: Dr. Elisabeta Lusso Durham Univ. N CoI: Prof. Simon L. Morris Durham Univ. N CoI: Dr. Casey Papovich Texas A & M University N CoI: Dr. Celine Peroux European Southern Observatory - Germany N CoI: Dr. Norbert Pirzkal Space Telescope Science Institute N CoI: Dr. Laura Prichard Space Telescope Science Institute N CoI: Dr. Tom Theuns Durham Univ. N CoI: Dr. Fabrizio Arrigoni Battaia Max Planck Institute for Astrophysics N CoI: Mitchell Revalski Georgia State University Research N Foundation ------------------------------------------------------------------------------------ Abstract We propose an 8 orbit WFC3/UVIS F336W imaging program in the MUSE Ultra Deep Field to obtain a deep view of galaxy star formation histories and morphologies at the peak and decline of cosmic star formation (z<2.5). Our program is made unique by two main factors. First, this proposal is built upon the synergy of two public observational programs in this field, a MUSE survey and the deepest HST grism survey with the WFC3/G141 grism. Second, the choice of the field, which hosts several rich galaxy groups at z=0.7-1.1 and two quasars separated by less than 500 kpc at z=3.2. The quasars act as light beacons to probe the gas in and around the group galaxies, making this field ideal for studies of the interaction of galaxies with their local environment. Taking advantage of the unrivaled HST capabilities in the UV, we aim to observe galaxies transitioning from the star forming main sequence to a passive population. Our goals are twofold. i) We will accurately quantify the recent star formation histories of the galaxies and their dust content, which, when complemented by the gas budget, will unveil the physical processes responsible for the onset of a population of passive objects down to 10^9 Msun in stellar mass. ii) We will study the morphology of the young stellar populations probed by the rest-frame far-UV images, which compared to the morphologies of the bulk of the stellar emission and of the nebular emission maps (from the WFC3/IR program), will yield a resolved view of the quenching events. This proposal enables new science goals in this unique field, greatly increasing its legacy value for the astrophysical community. ------------------------------------------------------------------------------------ 15968( 2) - 09-Jul-2019 17:22:15 - [ 2] Observations Description ------------------------ This program images the MUSE+HST Ultra Deep Field with the WFC3/UVIS F336W filter to obtain rest-frame UV imaging data. Full orbit integrations are obtained in order to minimize post-flash and read-noise and maximize the total depth. Therefore 4 orbit vists are required to enable fully cleaning the cosmic rays (as described in our phase I). Exposures are post-flashed by 4e- to help mitigate the CTE, and reach 12e- backgrounds per pixel. The dither pattern per visit is set 19 times larger than the default box pattern to help minimize the blotchy pattern observed in F336W imaging (i.e., similar to that seen in Rafelski et al. 2015, AJ, 150 31, Figure 15) and to dither over the chip gap to ensure a minimum of 7 exposures covering the entire field. As discussed in our phase I, we require an orient that is ~0, 90, or 180 degrees from whatever orient the first visit executes at to maximize our overlap of the two visits, as non-overlap regions will not have enough exposures to fully clean the cosmic rays from orbit long exposures. Therefore, the second visit is set to within 10 degrees of a 90 degree rotation. Also as described in the Phase I, to maximise the scientific return of this data in combination with the MUSE and WFC3/IR data we wish to observe this target within 1 year of the completion of the WFC3/IR observations (PID: 15673) which is currently foreseen for September 2019. Our program is not significantly affected by the possibility of one gyro mode. If we were to go into one gyro mode, it may affect the schedulability of the second orientation. We could accept the same orient or 180 degree rotation instead of the 90 degree rotation we are currently using. Note: if we did switch orients, we would need to add an offset for the second visit to maximize the dither pattern usefullness. ------------------------------------------------------------------------------------ 15968( 2) - 09-Jul-2019 17:22:15 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 6 MUDFQ2139-44 GALAXY, HIGH REDSHIFT RA=21H42M25.0175S, J2000 V = 16.64 34-UV GALAXY, QSO DEC=-44D19'44.86" Reference Frame: ICRS 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 ------------------------------------------------------------------------------------------------------------------------------------ 15968( 2) - 09-Jul-2019 17:22:15 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 3.287 Line_Spacing 2.128 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 15968( 2) - 09-Jul-2019 17:22:15 - [ 5] Visit: 01 Visit Requirements: SCHED 100%; BEFORE 01-SEP-2020:00:00:00 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 MUDFQ2139-4 WFC3/UVI ACCUM UVIS-CENT F336W FLASH=4 1 2588 S PATTERN 1 1 434-UV S ER (10445 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 | ------------------------------------------------------------------------------------------------------------------------------------ MUDFQ2139-4434-UV 1 WFC3/UVI ACCUM UVIS-CEN F336W 1 none none none 1 N/A S TER MUDFQ2139-4434-UV 1 WFC3/UVI ACCUM UVIS-CEN F336W 2 none none none 2 2619.0 S S TER MUDFQ2139-4434-UV 1 WFC3/UVI ACCUM UVIS-CEN F336W 3 none none none 3 2619.0 S S TER MUDFQ2139-4434-UV 1 WFC3/UVI ACCUM UVIS-CEN F336W 4 none none none 4 2619.0 S S TER 15968( 2) - 09-Jul-2019 17:22:15 - [ 6] Visit: 02 Visit Requirements: SCHED 100%; ORIENT 85D TO 95D FROM 01; BEFORE 01-SEP-2020:00:00:00 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 MUDFQ2139-4 WFC3/UVI ACCUM UVIS-CENT F336W FLASH=4 1 2588 S PATTERN 1 1 434-UV S ER (10445 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 | ------------------------------------------------------------------------------------------------------------------------------------ MUDFQ2139-4434-UV 1 WFC3/UVI ACCUM UVIS-CEN F336W 1 none none none 1 N/A S TER MUDFQ2139-4434-UV 1 WFC3/UVI ACCUM UVIS-CEN F336W 2 none none none 2 2619.0 S S TER MUDFQ2139-4434-UV 1 WFC3/UVI ACCUM UVIS-CEN F336W 3 none none none 3 2619.0 S S TER MUDFQ2139-4434-UV 1 WFC3/UVI ACCUM UVIS-CEN F336W 4 none none none 4 2619.0 S S TER 15968( 2) - 09-Jul-2019 17:22:15 - [ 7] Summary Form for Proposal 15968 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=4 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 01-SEP-2020:00:00:00, ORIENT 85D TO 95D FROM 01, PATTERN 1 1, SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W ------------------------------------------------------------------------------------------------------------------------------------ Target Names MUDFQ2139-4434-UV ------------------------------------------------------------------------------------------------------------------------------------