Submited on 25 Feb 3:10 am. Assigned ID: 306 ----- Attempting Submission 1 (Fri Feb 25 08:12:38 GMT 2011) ----- HST Phase I Proposal 306 (APT_J1042.apt) successfully submitted. ----- Attempting Submission 2 (Fri Feb 25 22:18:02 GMT 2011) ----- HST Phase I Proposal 306 (APT_J1042.apt) successfully submitted. ----- Attempting Submission 3 (Fri Feb 25 22:25:25 GMT 2011) ----- HST Phase I Proposal 306 (APT_J1042.apt) successfully submitted. This is proposal for 1 orbit of G140L. The source is faint enough and is not expected to cause any damage to the detector. ----- Attempting Submission 1 (Fri Jul 08 03:44:16 GMT 2011) ----- HST Phase II Proposal 12467 (APT_12467_PhaseII_Borthakur3.apt) successfully submitted. ----- Attempting Submission 2 (Fri Jul 08 03:50:34 GMT 2011) ----- HST Phase II Proposal 12467 (APT_12467_PhaseII_Borthakur_sub1.apt) successfully submitted. ----- Attempting Submission 3 (Mon Jul 18 18:02:20 GMT 2011) ----- HST Phase II Proposal 12467 (APT_12467_PhaseII_Borthakur_sub2.apt) successfully submitted. ----- Attempting Submission 4 (Mon Jul 18 18:11:35 GMT 2011) ----- Following are the warnings 1. If the target coordinates are not known to 0.4" (or better) an ACQ/SEARCH should precede the ACQ/IMAGE. See description 2. For the best data quality, it is strongly recommended that all four FP-POS positions be used when observing at a given COS CENWAVE setting. For the best data quality, it is strongly recommended that all four FP-POS positions be used when observing at a given COS CENWAVE setting. 3. Health/Safety warning flag. First warning is irrelevant as the error in RA and Dec of the target is 0.1" i.e. better than 0.4". The second warning concerning the recommendation is not followed as we have a very short exposure and switing FP-POS cause extreme loss of time. It is also not required for the goal of the project which is to detect FUV flux and check of Lyman-limit systems. Nevertheless, we had contacted William Januszewski (our PC) and Julia Duval regarding this. Julia suggested that we should avoid FP-POS=3, and hence we have used FP-POS=4. The health and safety flag is on. However our calculation, COS ETC IDs 201202 and 201209, based on the QSOs Galex NUV flux shows that the proposed exposures are well within the safe limits. QSO-galaxy pairs with small impact parameters of few kpcs are very rare. The QSO-galaxy pair J104257.5+074850.5-GQ1042 is a unique system that presents us with the opportunity to study the stellar disk of an extragalactic source using a background QSO at an impact parameter of 1.7 kpc. In addition, the background QSO is bright in the UV as well as radio frequencies, thus allowing us to probe the cold (21 cm HI) gas as well as warmer components enveloping it. Taking advantage of the radio brightness of the quasar, we have obtained high spectral (0.3 km/s) and spatial (parsec-scale) resolution data and detected a very narrow (3.6 km/s) absorber of column density of ~1x10^20 cm^{-2}. We found significant variations in the optical depth within the cloud (cloud of size ~14x27 pc). We request HST time to observe this QSO-galaxy pair with COS for a pilot study to check for presence of any Lyman limit system and estimate the HI column density. This study aims to probe the warmer phases of gas associated with the cold 21 cm absorber. This will provide us with a good understanding of multi-phase ISM cloud structures in this dwarf spiral galaxy. This system is one of the few galaxies outside our local group where we can study the ISM within the stellar disk at such small scales. This makes it an excellent test bed for ISM theories in dwarf galaxies and for studying how (if real) ISMs of smaller galaxies differ from those of bigger galaxies such as the Milky Way.

GQ1042 is a unique dwarf galaxy with a background UV bright QSO behind its stellar disk thus enabling us to study the ISM in its disk. In this pilot project we aim to check if there is any Lyman limit system in the FUV range. This in turn will prove if a high-resolution UV study is possible. Our primary goal is to understand the ISM of the dwarf-isolated galaxy, GQ1042. The purpose of this pilot project is to find out the following: 1. If future high-resolution COS observations of this target is feasible. 2. The strength of the Lyman-alpha transition associated with the target. The strength of this transition when put together with the available 21cm radio observations of the gas will provide us with the spin temperature of the gas. The project uses COS FUV grating G140L for 1 orbit in order to achieve the above mentioned goals. The 2221sec observations for the QSO with FUV of 20.15 +/- 0.22 mags at 1225 A (Ly-alpha of foreground galaxy) will result in a S/N >6 (COS.sp.201236). As a safety check, a magnitude higher source (i.e FUV = 19.15 mag) when observed for 2221 secs will yield 229 cts/s for the entire detector (COS.sp.201237). For the target acquisition we use NUV MIRROR A imaging setting for 34 secs, based on the ETC estimate (ID: 201202) for the QSO with NUV=19.75 +/-0.1 mags or 19.85 mags in the worst case scenario based on error estimate. This exposure will have a count rate for the entire detector of 826 cts/s and for the brightest pixel 6 cts/s. To check the safety of the aquisition exposures, we estimate the counts for an exposure of 34 secs for a source 1 mag brighter, i.e NUV=18.75 +/- 0.1 mags or 18.65 mags including the error margin, to 20 cts/s for the brightest pixel and 923 cts/s for the entire detector. Hence, we conclude that both the exposures are within safe limits for the detectors. ISM AND CIRCUMSTELLAR MATTER 12 false 0.0 0.0 false false false false SUPPORTED GALAXY LSB QSO Coordinates taken from DR7 of SDSS. J2000 J2000 GALEX FUV = 20.15+/-0.22 mags, NUV = 19.75+/-0.10 mags COS/FUV Spectroscopic No No G140L 1280 COS/FUV Spectroscopic No No G130M 1309 1311011883749 /private/var/folders/lK/lKE6i4EB2Ratn++BYoci6++++TI/-Tmp-/OPVisit3696365535895212502.xml The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. 1 orbit of G140L. The QSO lies behind a low surface brightness galaxy. GALEX FUV flux is recorded at the position of the QSO, and this observation is designed to test whether the FUV flux arises from the QSO (or, instead, from the galaxy). (Tic-Visit :proposal-id 12467 :visit-id "01" :proposal-version -1 :trans-version "20110509" :date "18-Jul-2011 13:58:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 104480 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12467 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12467 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2908 :al-overhead-at-end 0 :internal-dur-at-end 352 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3242 :pcs-gap 0 ) true 1 0 The amount of time on-target is small. We therefore include no additional FP-SPLITs.