The fate of infalling gas during its final approach onto the Milky Way disk

0 Assigned ID: 221 ----- Attempting Submission 1 (Thu Apr 06 13:10:40 GMT 2017) ----- HST Phase I Proposal 221 (Smith_Cloud.apt) successfully submitted. Receipt: # 221-1 ----- Attempting Submission 2 (Fri Apr 07 07:16:14 GMT 2017) ----- HST Phase I Proposal 221 (Smith_Cloud.apt) successfully submitted. Receipt: # 221-2 ----- Attempting Submission 3 (Fri Apr 07 21:20:51 GMT 2017) ----- HST Phase I Proposal 221 (Smith_Cloud.apt) successfully submitted. Receipt: # 221-3 0 For the best data quality, it is strongly recommended that the maximum number of allowed FP-POS positions is used when observing at a given COS CENWAVE setting. See full description for details. INEFFICIENT ORDERING OF FP-POS POSITIONS For the best data quality, it is strongly recommended that the maximum number of allowed FP-POS positions is used when observing at a given COS CENWAVE setting. See full description for details. INEFFICIENT ORDERING OF FP-POS POSITIONS I checked with my Contact Scientist and we've edited the exposure time accordingly to account for overages and under used exposure time. 1130272179 ----- Attempting Submission 1 (Mon Jul 10 02:17:43 GMT 2017) ----- ----- Attempting Submission 2 (Wed Dec 12 17:47:59 GMT 2018) ----- I checked with my Contact Scientist who said the FP-POS warning can be ignored. The Contect Scientist also indicated that I am using the correct FP-POS number. The fate of infalling gas during its final approach onto the Milky Way disk The Smith high-velocity cloud is an advanced stage of falling onto the Milky Way's disk. Its compressed head, comatary morphology structure, and diffuse tail---as well as the adjacent cloud fragments along its length---all indicate that this cloud is interacting strongly with its environment. The Smith Cloud has been studied extensively, making it an ideal candidate to assess the mechanisms that disrupt gas as it is deposited onto an Lstar galaxy and to assess how efficiently this S/H = 0.5 solar metallicity cloud disperses metals into the surrounding coronal gas. We will explore the properties of a cloud that recently splintered off the main body of the Smith Cloud using new HST/COS/G130M observations toward 2 QSOs. We will compare this freshly stripped cloud fragment with the gas in the wake of the Smith Cloud, which is in an advanced state of mixing, using published HST/COS/G130M observations toward 3 QSOs. We will combine these observations with already acquired spectroscopically resolved HI 21-cm (0.03 kpc resolution) and H-alpha (0.2 kpc resolution) emission maps to investigate how efficiently the surrounding coronal gas and ionizing radiation field are disturbing this cloud. Using spatial maps of the ionization conditions, chemical composition, and gas motions of a high-velocity cloud, we will further develop a model which uses hydrodynamical simulations with metal mixing and gas condensation to describe the evaporation timescale of galactic fountains as they flow onto Lstar galaxies. This is a 7-orbit proposal to observe two background QSO targets in the direction of the Smith Cloud. V01 observes a QSO (GALAX-J204402.0-075809, z=0.1034) using the COS G130M grating with central wavelength set to 1291 AA for 3 orbits. It uses an ACQ/IMAGE with MIRRORB. We will also use the 2 FP-POS positions to dither the placing of the spectrum on the grating. V02 observes a QSO (GALAX-J20333589-0320385, z=0.6964) using the COS G130M grating with central wavelength set to 1291 AA for the 4 orbits. It uses an ACQ/IMAGE with MIRRORB. We will also use the 2 FP-POS positions to dither the placing of the spectrum on the grating. Galaxies and the IGM 6 false false false false false false false SUPPORTED ISM ABSORPTION LINE SYSTEM - GALACTIC HIGH VELOCITY CLOUD NO This object was generated by the targetselector and retrieved from the GALEX database. J2000 J2000 GALEX FUV MAG = 17.78, Magnitude give in B (V MAG unavailible) ISM ABSORPTION LINE SYSTEM - GALACTIC HIGH VELOCITY CLOUD NO This object was generated by the targetselector and retrieved from the GALEX database. J2000 J2000 GALEX FUV MAG = 17.74 NUV MAG=17.07 COS/FUV Spectroscopic No No G130M 1291 COS/FUV Spectroscopic No No G130M 1291 1544636408750 The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. /private/var/folders/6_/0brg5c1d7vj284m1wqb2gd380000gn/T/OPVisit3937291852557407619.xml (Tic-Visit :proposal-id 15161 :visit-id "01" :proposal-version -1 :trans-version "20181130" :date "12-Dec-2018 11:40:08.0" :trans-errors '(:WARNINGS 1 :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 208848 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15161 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15161 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2812 :al-overhead-at-end 0 :internal-dur-at-end 86 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15161 :visit-id "01" :orbit-number 2 :pcs-time 302 :si-vis-utilization 2843 :al-overhead-at-end 0 :internal-dur-at-end 105 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15161 :visit-id "01" :orbit-number 3 :pcs-time 302 :si-vis-utilization 2843 :al-overhead-at-end 0 :internal-dur-at-end 398 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) true 3 0 1544636664203 /private/var/folders/6_/0brg5c1d7vj284m1wqb2gd380000gn/T/OPVisit5491464106875323912.xml The scheduling data was generated by CASM 26.2.2. CASM was run in Phase II mode. 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