Scientific Category is a required field. Science Keywords: Select from 2 to 5 items. 0 Assigned ID: 3871 ----- Attempting Submission 1 (Tue Nov 08 15:35:25 GMT 2022) ----- Joint NRAO/HST A detailed description of this program can be found in the "Proposal Description". This is the first time that I am preparing a Phase-II program in the APT. I have carefully explained all observing choices in the Proposal Description, but would appreciate feedback if for scientific or technical reasons you propose modifications of this Phase-II program. Thank you for your kind help. 703728615 ----- Attempting Submission 1 (Mon Dec 05 12:46:21 GMT 2022) ----- The baryon cycle of gas in and out of galaxies is fundamental for the evolution of galaxies, clusters, and AGN. Cold molecular gas plays a critical role, but it remains challenging to detect cold gas at the (sub)-kpc scales of individual star formation regions and AGN. To overcome these limitations, molecular gas can be traced in absorption against the background continuum of distant radio sources, but such absorption signals have been mysteriously absent at z>1. We present the first high-z absorption of CO(0-1) and methanol, associated with the proto-cluster radio galaxy B2 0902+34 (z=3.4). We propose to map the CO(0-1) absorption against the complex radio source at a resolution matching that of HST. Goal is to study the distribution, kinematics, and column density of the molecular gas on kpc scales, and compare this to the galaxies, star-forming regions, and circum-galactic clumps seen with HST. We will also confirm and resolve the two 113 GHz methanol absorbers, and target for free also HCN and HCO+, which all trace much denser molecular gas compared to CO. This proposal showcases a unique diagnostic for studying star formation in the Early Universe, and offers an exciting science case for the Next-Generation VLA. This HST project will collect a 1-orbit deep exposure in the WFC3/F105W filter of radio galaxy B2 0902+34 (z=3.34) and its surrounding environment. This will complement primary VLA observations of molecular gas in this system. The F105W filter was chosen to contain no strong emission lines, hence will observe pure starlight in the radio galaxy, surrounding galaxies, and circum-galactic medium. Dittering and artifact mitigation: The target region-of-interest is mostly the inner 10 arcsec around the target coordinates. We therefore choose the IR (rather than IR-fix) aperture, to place the target in the optimal default region of the CCD. We are interested in imaging the high-z galaxies, as well as detecting low surface brightness emission on this 10 arcsec scale, and possibly further out. Therefore, we aim to mitigate artifact (blobs) with a single 2-pointing wide ditter, with an additional single 4-point narrow box-ditter at each position to optimize the PSF response (8 exposures in total). By taking the 8 exposures at a different position on the CCD, we can also mitigate potential effects of Earth-shine or strong HeI 10,830 background, in case this would affect one or more of the exposures more than others. We have no experience with potential effects of HeI 10,830 contamination, but unless the HeI background is expected to severely limit our science case for detecting faint low-surface-brightness emission of circum-galactic starlight, we prefer not to use another filter, because those contain contaminating emission lines (e.g., F140W contains MgII, while F160W contains OII). Zodiacal effects: Our target is at an ecliptic latitude of 16.7 degrees. To mitigate the effects of zodiacal light that may limit detection of low-surface-brightness emission, we adjusted the start and end dates of the observing window to an effective sun avoidance limit of about 65 degrees (i.e., +-10 days compared to the default). Note, however, that we left the final 90 second of our nominal orbit visibility ununsed, which more than compensated for this by increasing the possible observing window of this 1-orbit program to about 55 percent (200 days/yr) visibility over the year. Since this HST program was awarded together with a primary VLA program, and no official Phase-I proposal was submitted through the APT, we kindly request the inclusion of this Visit timing requirement. Bright objects: While there are several relatively bright stars in the field, all of them are more than 1 arcmin away from our target region and have JHK mag between 12 and 13. Based on our limited experience with analyzing WFC3 images, we do not expect PSF-artifact of these stars to affect our target region. Reduced-gyro operations: we expect that our program is suitable for, and not negatively affected by, reduced-gyro operations. We do not put any limitations on the orientation, and the visibility window of this proposal (55 percent/200 days per year) is large enough that further restrictions should not limit scheduling of this 1-orbit program. N/A Galaxies Supermassive Black Holes and Active Galaxies 6 false false false false false false false SUPPORTED GALAXY HIGH REDSHIFT GALAXY LYMAN ALPHA CLOUD RADIO GALAXY This object was generated by the targetselector and retrieved from the SIMBAD database. Name was updated to reflect the B2 name of the radio source (for archival purposes), but coordinates did not change and were checked. NVSS-J090530+340756 J2000 J2000 G_AB=23.9, R_AB=23.0, K=18.8, WISE_W1=15.8 ( magnitudes) WFC3/IR Imaging No No F105W POS-TARG DITHER DITHER 4 5.183 WFC3-IR-DITHER-BOX-MIN false 74.653 true 0.365 0.572 2 41.859 POS-TARG WFC3-IR-DITHER-BLOB 18.528 1 true 1670243407326 /Users/bemonts/Documents/Proposals/VLA/VLA2023/HST_PhaseII/OP-cache/B20902_HST_PhaseII_v4-v01.xml The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17268 :visit-id "01" :proposal-version -1 :trans-version "20220630" :date "05-Dec-2022 07:29:59.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1810544 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17268 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17268 :visit-id "01" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2707 :al-overhead-at-end 0 :internal-dur-at-end 576 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3180 :pcs-gap 0 ) true 1 0