The Circumgalactic Medium of a Gas-Rich Ultra Diffuse Galaxy

0 Assigned ID: 2005 ----- Attempting Submission 1 (Fri Apr 09 16:23:54 GMT 2021) ----- INEFFICIENT ORDERING OF FP-POS POSITIONS INEFFICIENT ORDERING OF FP-POS POSITIONS INEFFICIENT ORDERING OF FP-POS POSITIONS INEFFICIENT ORDERING OF FP-POS POSITIONS INEFFICIENT ORDERING OF FP-POS POSITIONS Resubmission Oct 1 2021: ACQ exposure times reduced to change S/N of 40 to S/N of 20 2089134425 ----- Attempting Submission 1 (Mon Jul 19 13:21:08 GMT 2021) ----- ----- Attempting Submission 2 (Fri Oct 01 05:04:11 GMT 2021) ----- Only 2 FP-POSs are available for this mode, and FP-POS=3 followed by FP-POS=4 is the more effecient order The Circumgalactic Medium of a Gas-Rich Ultra Diffuse Galaxy 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. 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. Dr. David Bowen is a Research Astronomer in the Astrophysical Sciences department of Princeton University. He has over 30 years experience designing programs to study the distribution of baryons in the universe. He has lead more than 22 programs using HST, the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Galaxy Evolution Explorer (GALEX). Dr. Edward Jenkins is also a Research Astronomer at Peyton. He is a world leader in the analysis of the interstellar medium (ISM) and has pioneered numerous techniques in the analysis of satellite-based data. In several cases he has led or participated significantly in the development of space missions (e.g. Copernicus, IMPAS). Prof. Todd Tripp is a professor at the Univ. of Mass and is one of the preeminent experts in the study of the intergalactic medium and the circumgalactic medium (CGM), as well as the ISM of our own Milky Way. He too has extensive expertise in the analysis of HST data and has led several large COS programs. Intergalactic Medium and the Circumgalactic Medium Galaxies 6 false false true false false false false false SUPPORTED GALAXY QSO NO SDSSJ143348.21+012937.6 J2000 J2000 GALEX FUV = 33 micro-Jy COS/FUV Spectroscopic No No G130M 1291 1633064458162 /private/var/folders/3w/3cmkcm694574ksd8zvyxvkgh0000gn/T/OPVisit14205559995368715517.xml The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. 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CASM was run in Phase II mode. (Tic-Visit :proposal-id 16680 :visit-id "02" :proposal-version -1 :trans-version "20210514" :date "01-Oct-2021 01:00:59.0" :trans-errors '(:WARNINGS 2 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 156768 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16680 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16680 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2748 :al-overhead-at-end 0 :internal-dur-at-end 48 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3142 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16680 :visit-id "02" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2748 :al-overhead-at-end 0 :internal-dur-at-end 57 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3142 :pcs-gap 0 ) (Tic-Orbit :proposal-id 16680 :visit-id "02" :orbit-number 3 :pcs-time 392 :si-vis-utilization 2748 :al-overhead-at-end 0 :internal-dur-at-end 353 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3142 :pcs-gap 0 ) true 3 0 Exposure time for a SNR = 20 assuming 50% of GALEX FUV flux