Skeletons in the Cluster: Unveiling the Stellar Mass Backbone of z=1.6 Galaxies

0 Assigned ID: 4511 ----- Attempting Submission 1 (Wed May 24 19:02:51 GMT 2023) ----- HST Phase I Proposal 4511 successfully submitted. Receipt: # 4511-1 ----- Attempting Submission 2 (Wed May 24 22:15:24 GMT 2023) ----- Second submission - used Jay Anderson's empirical relationship to convert dithers from pixels to pos targs in arcseconds - used a larger +/- 1.5 arcsec offsets between starting positions of orbits -817875320 ----- Attempting Submission 1 (Thu Sep 14 20:24:48 GMT 2023) ----- ----- Attempting Submission 2 (Mon Nov 06 22:22:47 GMT 2023) ----- Skeletons in the Cluster: Unveiling the Stellar Mass Backbone of z=1.6 Galaxies The conversion of gas into stars on small spatial scales, and its connection to the underlying stellar backbone is key to understanding quenching in cluster galaxies. However, the dearth of high-resolution maps of the molecular gas, star formation, and stars has made it impossible to understand these processes. Recently, a new window into spatially-resolved molecular gas and far-IR emission has been opened through ALMA observations of high-redshift clusters. These gains have been mainly due to the high source density of star forming galaxies in young clusters, which allows for large multiplexing. The ALMA observations have delivered spatial and kinematic maps of the molecular gas at exquisite resolution for the first large sample of high-redshift galaxies, while the available rest-frame UV HST and ALMA FIR data have yielded star formation maps. We will combine these novel ALMA and HST data with new imaging in F105W, F140W, and F160W to derive stellar mass maps and to investigate the spatial distribution of the dominant baryonic components in main-sequence cluster galaxies at z~1.6. The target cluster contains galaxies in remarkable states of transformation and will be combined with analogous available data on 2 other z~1.6 clusters for a total sample of 29 galaxies at the same redshift with high-resolution spatial maps of their star formation, stellar mass, and gas. With these data we will, for the first time: 1) measure where star formation in cluster galaxies is halted (outskirts, centers, or everywhere); 2) connect deviations from scaling relationships to the stellar backbone of the galaxy; and 3) learn what role clumps play in driving mass buildup in cluster galaxies. The goal of this program is to obtain WFC3 imaging over a galaxy cluster at z=1.6 in three filters: F105W (4.5 orbits), F140W (1.5 orbits), and F160W (1 orbit). The observations are designed to cover in-hand ALMA, WFC3, and ACS imaging; the pointing coordinates have been chosen to maximize overlap with these images, in particular the existing (shallower) F160W imaging. Most of the primary targets of interest are within the central 80x80" diameter, with K band fluxes around 21-23 mags, and effective radii averaging around 0.7". We do not place orient constraints to maximize schedulability. Orbit / visit strategy: ----------------- Each visit consists of 1-2 orbits, over various filters. Visit 1 = 1 orbit in F140W and 1 orbit in F105W Visit 2 = 1/2 orbit in F140W and 1/2 orbit in F105W Visit 3 = 1 orbit in F160W and 1 orbit in F105W Visit 4 = 2 orbits in F105W In visits which contain F105W with another filter, we have placed the F105W exposures toward the middle of the orbit to help reduce the sky background from the airglow line of He I, which can affect some orbits. In these visits, the 4-point dither pattern (described below) for each filter is thus split over 2 orbits, which also reduces pointing maneuvers. Dithering strategy: --------------- We use a dither pattern with a combination of 1/2 pixel shifts to improve sampling of the PSF, and integer pixel shifts to enable rejection of hot/bad pixels and mitigate persistence from bright compact sources. We use a larger version of the standard WFC3-IR-DITHER-BOX-MIN pattern, which has only 1-4 pixel offsets between pointings. As some bad pixels come in clumps we prefer a slightly larger pattern. We use POS-TARG offsets to execute our dither pattern. The general 4-point dither pattern we use is: POS-TARG: (0,0) (1.36,0.428) (0.884,1.216) (-0.476,0.788) pixels: (0,0) (10.0,3.5) (6.5,10.0) (-3.5,6.5) To further mitigate for blobs, which can be 10-15 pixels in size, we apply shifts of +/-1.5 arcseconds in x and y to the starting position of the dither pattern for F105W and F140W filters, which have multiple orbits over several visits. This is again done through POS-TARG offsets, with the subsequent dither positions following the same overall pattern as above, calibrated to the new starting point. No attempt is made to dither over the "Death Star", as large dithers introduce large differential distortion. Our team consists of co-Is with a vast range of expertise on topics related to this proposal, bridging observational to modeling and theoretical perspectives. We all have an extensive background in galaxy evolution, cluster formation, and understanding the processes that quench star formation, using both imaging and spectroscopic techniques over multiple wavelengths. Many co-Is are PIs and/or key members of large galaxy cluster collaborations (e.g. SpARCS, GOGREEN, GCLASS). We highlight specific areas of expertise below and list the relevant team members. Photometric data reduction and analysis: Rudnick, Balogh, Muzzin, Wilson, Nantais, Noble, Cramer, Pigarelli, Yee, Demarco. Noble is the PI of the HST/UV imaging for the proposed cluster as well as J0224 and J0330 for which we have existing data. Wilson is the PI of HST/F160W imaging for all three clusters. All other in-hand HST imaging on J0224 and J0330 is public archival data. Cold gas and dust observations with ALMA: Noble, Pigarelli, Cramer, Rudnick, Webb, Kamieneski, van Kampen. Noble is the PI of all the CO/FIR ALMA data related to the program (both archival and private). Theoretical predictions from cosmological hydrodynamic simulations: Bahe works with the Hydrangea simulation suite and is a core member of the next-generation COLIBRE simulation program. Quenching and galaxy structural evolution: Vulcani, Balogh, Rudnick, Muzzin, Cooper, Bahe, Noble. Galaxies 6 false false false false false false false false SUPPORTED CLUSTER OF GALAXIES HIGH REDSHIFT CLUSTER J2000 J2000 K = 22 WFC3/IR Imaging No No F160W WFC3/IR Imaging No No F140W WFC3/IR Imaging No No F105W WFC3/IR Imaging No No F105W 1719333551798 /private/var/folders/b9/jx3rgsbx0tgf9j1xp52tw6km0005ml/T/OPVisit18077017983597034751.xml The scheduling data was generated by CASM 32.1.1. CASM was run in Phase II mode. 1 orbit in F140W and 1 orbit in F105W, each with 4-point dither pattern -2 exposures of F105W are in the middle of each orbit, with F140W at start and end of orbit to mitigate airglow issues with F105W (Tic-Visit :proposal-id 17439 :visit-id "01" :proposal-version -1 :trans-version "20240604" :date "25-Jun-2024 12:39:11.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1949792 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17439 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17439 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2599 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3005 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17439 :visit-id "01" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2579 :al-overhead-at-end 0 :internal-dur-at-end 310 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3005 :pcs-gap 0 ) true 2 0 dither position 1 pos targ: 0",0" (0, 0 pixels) dither position 1 pos targ: 0",0" (0, 0 pixels) dither position 2 pos targ: 1.36", 0.428" (10, 3.5 pixels) dither position 2 pos targ: 1.36", 0.428" (10, 3.5 pixels) dither position 3 pos targ: 0.884", 1.216" (6.5, 10 pixels) dither position 3 pos targ: 0.884", 1.216" (6.5, 10 pixels) dither position 4 pos targ: -0.476",0.788" (-3.5, 6.5 pixels) dither position 4 pos targ: -0.476",0.788" (-3.5, 6.5 pixels) 1719333552614 /private/var/folders/b9/jx3rgsbx0tgf9j1xp52tw6km0005ml/T/OPVisit7439899325484419826.xml The scheduling data was generated by CASM 32.1.1. CASM was run in Phase II mode. 0.5 orbit in F140W and 0.5 orbit in F105W, each with 4-point dither pattern -4 exposures of F105W are in the middle of orbit, with 2 F140W exposures at the start and end of orbit to mitigate airglow issues with F105W -starting position has been offset by -1.5", 1.5", with same dither pattern (Tic-Visit :proposal-id 17439 :visit-id "02" :proposal-version -1 :trans-version "20240604" :date "25-Jun-2024 12:39:12.0" :trans-errors '(:WARNINGS 1 :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 1009728 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17439 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17439 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2606 :al-overhead-at-end 0 :internal-dur-at-end 595 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3005 :pcs-gap 0 ) true 1 0 dither position 1 pos targ: -1.5", 1.5" (-11.0, 12.4 pixels) dither position 2 pos targ:-0.14",1.928" (-1.0, 15.9 pixels) dither position 1 pos targ: -1.5", 1.5" (-11.0, 12.4 pixels) dither position 2 pos targ:-0.14",1.928" (-1.0, 15.9 pixels) dither position 3 pos targ: -0.616", 2.716" (-4.5, 22.4 pixels) dither position 4 pos targ: -1.976", 2.288" (-14.5, 18.9 pixels) dither position 3 pos targ: -0.616", 2.716" (-4.5, 22.4 pixels) dither position 4 pos targ: -1.976", 2.288" (-14.5, 18.9 pixels) 1719333553412 /private/var/folders/b9/jx3rgsbx0tgf9j1xp52tw6km0005ml/T/OPVisit5294577331458628593.xml The scheduling data was generated by CASM 32.1.1. CASM was run in Phase II mode. 1 orbit in F160W and 1 orbit in F105W, each with 4-point dither pattern -2 exposures of F105W are in the middle of each orbit, with F160W at start and end of orbit to mitigate airglow issues with F105W -starting position has been offset by -1.5", -1.5", with same dither pattern (Tic-Visit :proposal-id 17439 :visit-id "03" :proposal-version -1 :trans-version "20240604" :date "25-Jun-2024 12:39:13.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1949792 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17439 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17439 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2602 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3005 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17439 :visit-id "03" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2582 :al-overhead-at-end 0 :internal-dur-at-end 310 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3005 :pcs-gap 0 ) true 2 0 dither position 1 pos targ: -1.5", -1.5" (-11.0,-12.3 pixels) dither position 1 pos targ: -1.5", -1.5" (-11.0,-12.3 pixels) dither position 2 pos targ: -0.14", -1.072" (-1, -8.8 pixels) dither position 2 pos targ: -0.14", -1.072" (-1, -8.8 pixels) dither position 3 pos targ: -0.616", -0.284" (-4.5, -2.3 pixels) dither position 3 pos targ: -0.616", -0.284" (-4.5, -2.3 pixels) dither position 4 pos targ: -1.976", 0.712" (-14.5, -5.8 pixels) dither position 4 pos targ: -1.976", 0.712" (-14.5, -5.8 pixels) 1719333554265 /private/var/folders/b9/jx3rgsbx0tgf9j1xp52tw6km0005ml/T/OPVisit17289778071323727463.xml The scheduling data was generated by CASM 32.1.1. CASM was run in Phase II mode. two full orbits in F105W, over 4-point boxed dither pattern -pos4: starting position has been offset by 1.5", -1.5", with same dither pattern -pos5: starting position has been offset by 1.5", 1.5", with same dither pattern (Tic-Visit :proposal-id 17439 :visit-id "04" :proposal-version -1 :trans-version "20240604" :date "25-Jun-2024 12:39:14.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1914960 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17439 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17439 :visit-id "04" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2615 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3005 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17439 :visit-id "04" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2592 :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 3005 :pcs-gap 0 ) true 2 0 dither position 1 pos targ: 1.5", -1.5" (11.0, -12.4 pixels) dither position 2 pos targ: 2.86", -1.072" (21.0, -8.9 pixels) dither position 3 pos targ: 2.384", -0.284" (17.5, -2.4 pixels) dither position 4 pos targ: 1.024", -0.712" (7.5, -5.9 pixels) dither position 1 pos targ: 1.5", 1.5" (11.0, 12.3 pixels) dither position 2 pos targ: 2.86", 1.928" (21.0, 15.8 pixels) dither position 3 pos targ: 2.384", 2.716" (17.5, 22.3 pixels) dither position 4 pos targ: 1.024", 2.288" (7.5, 18.8 pixels)