16680( 3) - 01-Oct-2021 13:27:31 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16680 Version: 3 Check-in Time: 01-Oct-2021 13:27:31 STScI Edit Number: 0 Title The Circumgalactic Medium of a Gas-Rich Ultra Diffuse Galaxy ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. David V. Bowen Princeton University Y CoI: Prof. Todd M. Tripp University of Massachusetts - Amherst N CoI: Dr. Edward B. Jenkins Princeton University N ------------------------------------------------------------------------------------ Abstract Ultra Diffuse Galaxies (UDGs) are galaxies with large effective radii but very low surface brightness. They were recently discovered in unprecedented numbers in the Coma Cluster, and are now being found in galaxy groups, and in isolation in the field. Their origin remains far from clear. In this proposal, we request time to observe a QSO that lies behind a gas rich UDG, using the COS G130M grating, in order to search for absorption lines from the interstellar and circumgalactic medium of the galaxy. The sightline to the QSO LBQS 1431+0142 passes within 11 kpc of the UDG ACG 242019, a galaxy with an HI mass of 6x10^8 solar masses, recovered recently in the ALFALFA survey from its 21 cm emission. This HI mass favors the detection of HI with a high column density in absorption towards the background QSO, which, in combination with metal lines, can be used to measure the metallicity of the CGM gas in the UDG. Such data can help constrain the origin of the galaxy. Comparison of our results with those from the population of Damped Lyman-alpha systems at higher redshift will begin to examine whether UDGs might contribute significantly to the population of QSO Absorption Line Systems in the universe. ------------------------------------------------------------------------------------ Observations Description ------------------------ These are G130M obseravtion of a single AGN that lies close to a ultra diffuse galaxy galaxy. The most important absorption lines expected from the intervening galaxy is Lyman-alpha and SiIII 1206. As the foreground galaxy is at low redshift, these lines are at wavelengths near geocoronal Lyman-alpha. We therefore need to use the remaining G130M 1291 grating setting to observe them. We utilize the 2 available FP-POS positions to mitigate the effects of large-scale defects. There will be a gap left between 1274-1294A which can no longer be filled using a different grating setting, but few absorption lines from the intervening galaxy is expected at these wavelengths. ------------------------------------------------------------------------------------ 16680( 3) - 01-Oct-2021 13:27:31 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 LBQS1431+014 GALAXY, QSO RA=14H33M48.2100S +/- 0.1", J2000 Z = V = 18.35 GALEX FUV = 33 micro-Jy 2 DEC=+01D29'37.60" +/- 0.1" 0.211 Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 16680( 3) - 01-Oct-2021 13:27:31 - [ 3] Visit: 01 (Visit 1) 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 LBQS1431+01 COS/NUV ACQ/IMA PSA MIRRORA 1 11 S (11 42 GE S) Comments: Exposure time for a SNR = 20 assuming 50% of GALEX FUV flux ------------------------------------------------------------------------------------------------------------------------------------ 2 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, SEGMENT=BOTH, 1 1086 S 42 G BUFFER-TIME=5642 see below (1149 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, SEGMENT=BOTH, 1 1086 S 42 G BUFFER-TIME=5642 see below (1149 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 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 | ------------------------------------------------------------------------------------------------------------------------------------ LBQS1431+0142 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE LBQS1431+0142 2 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 1149.0 S G 16680( 3) - 01-Oct-2021 13:27:31 - [ 4] 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 | ------------------------------------------------------------------------------------------------------------------------------------ LBQS1431+0142 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 1149.0 S G LBQS1431+0142 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 N/A G LBQS1431+0142 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 N/A G LBQS1431+0142 6 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A G LBQS1431+0142 7 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A G LBQS1431+0142 8 COS/FUV TIME-TA PSA G130M 1291 none none none none 4 N/A G LBQS1431+0142 9 COS/FUV TIME-TA PSA G130M 1291 none none none none 4 N/A G 16680( 3) - 01-Oct-2021 13:27:31 - [ 5] Visit: 02 (Visit 2) 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 LBQS1431+01 COS/NUV ACQ/IMA PSA MIRRORA 1 11 S (11 42 GE S) Comments: Exposure time for a SNR = 20 assuming 50% of GALEX FUV flux ------------------------------------------------------------------------------------------------------------------------------------ 2 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, SEGMENT=BOTH, 1 1086 S 42 G BUFFER-TIME=5642 see below (1149 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, SEGMENT=BOTH, 1 1086 S 42 G BUFFER-TIME=5642 see below (1149 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=3, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 LBQS1431+01 COS/FUV TIME-TA PSA G130M 1291 FP-POS=4, SEGMENT=BOTH, 1 1280 S 42 G BUFFER-TIME=5642 (1280 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 | ------------------------------------------------------------------------------------------------------------------------------------ LBQS1431+0142 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE LBQS1431+0142 2 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 1149.0 S G LBQS1431+0142 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 1149.0 S G LBQS1431+0142 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 N/A G LBQS1431+0142 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 N/A G 16680( 3) - 01-Oct-2021 13:27:31 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ LBQS1431+0142 6 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A G LBQS1431+0142 7 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A G 16680( 3) - 01-Oct-2021 13:27:31 - [ 7] Summary Form for Proposal 16680 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=5642, FP-POS=3, FP-POS=4, SEGMENT=BOTH ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names LBQS1431+0142 ------------------------------------------------------------------------------------------------------------------------------------