16201( 2) - 26-Jun-2020 18:16:39 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16201 Version: 2 Check-in Time: 26-Jun-2020 18:16:39 STScI Edit Number: 0 Title Testing the Origin of Vast Extended Molecular Gas Outside High-z Post-Starbursts ------------------------------------------------------------------------------------ Type Cycle GO 28 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Justin Scott Spilker University of Texas at Austin Y CoI: Dr. Rachel Bezanson University of Pittsburgh N CoI: Prof. Jenny Emma Greene Princeton University N CoI: Prof. Mariska Kriek University of California - Berkeley N CoI: Ms. Katherine Suess University of California - Berkeley N CoI: Dr. Desika Narayanan University of Florida N CoI: David Setton University of Pittsburgh N CoI: Prof. Robert Feldmann Universitat Zurich N ------------------------------------------------------------------------------------ Abstract We have discovered spectacular vast molecular gas reservoirs extending tens of kpc outside of two high-redshift post-starburst galaxies as part of an ongoing ALMA CO survey of such objects. While the host galaxies are only 3-5kpc in size, nearly half the total CO luminosity in each system extends 25-45kpc from the hosts. This discovery was unexpected and both the scale and magnitude of the extended gas features are unprecedented at any redshift. The origin of the vast CO is unclear, but may be related to AGN outflows, tidal stripping, and/or environmental effects. We propose a low-cost, high-impact VLA+HST campaign to determine the origins of the remarkable gas features and their broader implications for galaxy evolution, including galactic feedback, the formation of extended stellar halos, and metal enrichment of the circumgalactic medium. The VLA data are designed to characterize the presence and effects of AGN - existing data cannot even rule out radio-loud AGN activity - while the HST data are needed to discover stellar tidal debris and/or close merging companions. Together these datasets can uniquely determine the origin of the incredible molecular gas features we have found and place this unexpected discovery in broader context. ------------------------------------------------------------------------------------ Observations Description ------------------------ This observing program will acquire 1-orbit depth WFC3-IR / F110W imaging of two z~0.6 post-starburst galaxies. The goal is to spatially resolve the galaxies themselves and search for tidal stellar streams, nearby companions, and other faint / low surface brightness emission. We will observe in four dither positions using the WFC3-IR-DITHER-BOX pattern in order to properly sample the PSF. We use a slighly larger dither pattern than the default, corresponding to pixel positions of (0, 0), (10.0, 3.5), (6.5, 10.0), and (-3.5, 6.5), because some bad pixels come in clumps. We do not attempt to dither over the IR blobs or the death star dead spot. To maximize our dynamic range, we will use STEP50 with NSAMP=15 at each dither position. We use a second exposure at a single dither position with NSAMP=14 to fill out the 16201( 2) - 26-Jun-2020 18:16:39 - [ 2] orbit. ------------------------------------------------------------------------------------ 16201( 2) - 26-Jun-2020 18:16:39 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 J1448+1010 GALAXY, HIGH REDSHIFT RA=14H48M45.9192S, J2000 V = 20.0 GALAXY, INTERACTING DEC=+10D10'10.55" GALAXY, TIDAL TAIL Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 2 J2258+2313 GALAXY, HIGH REDSHIFT RA=22H58M5.6750S, J2000 V = 20.5 GALAXY, INTERACTING DEC=+23D13'16.12" GALAXY, TIDAL TAIL Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 16201( 2) - 26-Jun-2020 18:16:39 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 1.42 Line_Spacing 0.919 Coordinate_Frame POS-TARG Pattern_Orient 17.370 Angle_Between_Sides 76.301 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16201( 2) - 26-Jun-2020 18:16:39 - [ 5] Visit: 01 (SDSS_J1448+1010) 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 J1448+1010 WFC3/IR MULTIAC IR F110W NSAMP=15, SAMP-SEQ=STEP50 1 DEF PATTERN 2 1 CUM (1996.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J1448+1010 WFC3/IR MULTIAC IR F110W NSAMP=14, SAMP-SEQ=STEP50 1 DEF CUM (449.234 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 | ------------------------------------------------------------------------------------------------------------------------------------ J1448+1010 1 WFC3/IR MULTIAC IR F110W 1 none none none 1 N/A CUM J1448+1010 1 WFC3/IR MULTIAC IR F110W 2 none none none 1 N/A CUM J1448+1010 1 WFC3/IR MULTIAC IR F110W 3 none none none 1 N/A CUM J1448+1010 1 WFC3/IR MULTIAC IR F110W 4 none none none 1 N/A CUM J1448+1010 2 WFC3/IR MULTIAC IR F110W none none none none 1 N/A CUM 16201( 2) - 26-Jun-2020 18:16:39 - [ 6] Visit: 02 (SDSS_J2258+2313) 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 J2258+2313 WFC3/IR MULTIAC IR F110W NSAMP=15, SAMP-SEQ=STEP50 1 DEF PATTERN 2 1 CUM (1996.937 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J2258+2313 WFC3/IR MULTIAC IR F110W NSAMP=14, SAMP-SEQ=STEP50 1 DEF CUM (449.234 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 | ------------------------------------------------------------------------------------------------------------------------------------ J2258+2313 1 WFC3/IR MULTIAC IR F110W 1 none none none 1 N/A CUM J2258+2313 1 WFC3/IR MULTIAC IR F110W 2 none none none 1 N/A CUM J2258+2313 1 WFC3/IR MULTIAC IR F110W 3 none none none 1 N/A CUM J2258+2313 1 WFC3/IR MULTIAC IR F110W 4 none none none 1 N/A CUM J2258+2313 2 WFC3/IR MULTIAC IR F110W none none none none 1 N/A CUM 16201( 2) - 26-Jun-2020 18:16:39 - [ 7] Summary Form for Proposal 16201 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=14, NSAMP=15, SAMP-SEQ=STEP50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W ------------------------------------------------------------------------------------------------------------------------------------ Target Names J1448+1010, J2258+2313 ------------------------------------------------------------------------------------------------------------------------------------