0 Assigned ID: 7197 ----- Attempting Submission 1 (Wed Apr 15 19:45:46 GMT 2026) ----- HST Phase I Proposal 7197 successfully submitted. Receipt: # 7197-1 ----- Attempting Submission 2 (Thu Apr 16 15:06:55 GMT 2026) ----- POS TARG & PATTERN should be used carefully with ACS ramp filters as central wavelengths & transmission efficiencies vary within the apertures. POS TARG & PATTERN should be used carefully with ACS ramp filters as central wavelengths & transmission efficiencies vary within the apertures. POS TARG & PATTERN should be used carefully with ACS ramp filters as central wavelengths & transmission efficiencies vary within the apertures. POS TARG & PATTERN should be used carefully with ACS ramp filters as central wavelengths & transmission efficiencies vary within the apertures. We adjusted the central wavelength settings for the ramp filters with respect to the phase 1 proposal. The ramp observations all aim to observe Ly alpha at the redshift of the targets. Table 3 in the proposal reporting the central wavelnegths is not correct since there are typos in the the column listing the wavelengths. We double checked that the redshifts of the targets are correct, and we recalculated the central wavelengths to target Ly alpha as specified in the the proposal's science goals. For target 4 TN J0924-2201 at z=5.197, the wavelength change requires to switch from FR716N (as pevified in the proposal) to FR782N because the redshifted wavelenth for Ly alpha at the redshift of the target is outside of the range covered by the FR716N filter. 199601807 ----- Attempting Submission 1 (Fri Aug 14 20:25:07 GMT 2026) ----- dither patterns are ok for ramp filters Jets, Mergers, and Feedback at Cosmic Dawn: HST-JWST Imaging of z > 4.4 Radio Galaxies We propose a joint HST-JWST imaging program targeting the four highest-redshift (z > 4.4) classical radio galaxies known (i.e. the complete accessible population) observed when the Universe was < 1.4 Gyr old. HzRGs pinpoint the most massive galaxies in the early Universe, are associated with protoclusters, and their powerful jets indicate rapidly spinning SMBHs. They provide unique laboratories for studying massive galaxy formation, SMBH growth, and jet-driven feedback at early epochs. Our program addresses four key questions: (1) How do jets drive feedback? HST maps rest-UV continuum and Ly alpha emission relative to the radio structure; JWST provides Balmer-break colors to distinguish jet-induced star formation from the older stellar body. (2) What triggers the jets? JWST rest-frame optical morphologies will reveal whether the merger-jet connection established at z=1-2.5 persists to z > 4.4, or whether coherent accretion dominates SMBH spin-up. (3) What is the AGN geometry? Anomalously high blazar counts at z > 4 suggest near-4pi obscuration; HST narrow-band Ly alpha imaging will test this by constraining ionization cone opening angles. (4) What is the large-scale environment? HST wide-field imaging covers 1 sqMpc, enabling a proto-cluster census. We compare radio-loud targets against matched radio-quiet Type 2 QSOs to isolate the effects of jets on their hosts and test whether mergers preferentially trigger radio-loud activity. This program provides the first rest-frame optical and UV morphologies of z > 4.4 steep-spectrum radio galaxies, constraining how jets, mergers, and feedback shaped the most massive galaxies in the early Universe. Each of the four targets will be observed with two HST broad-band filters (one optical, one near-IR) and one ACS narrow-band ramp filter centered on redshifted Lyalpha (Tabs. 2 and 3, Fig 3 in the proposal). ACS/WFC F775W (1 orbit each) will be obtained for 6C0140+326, RCJ0311+0507, and J1639+4052, sampling rest-frame ~1300-1400 A redward of Lyalpha. For TN J0924-2201 (z = 5.197), deep archival ACS F850LP imaging (5 orbits) provides equivalent coverage. WFC3/IR F140W (1 orbit each) will be obtained for 6C0140+326, RCJ0311+0507, and J1639+4052; TN J0924-2201 requires 2 orbits (F160W) to reach equivalent S/N. Lyalpha will be imaged with ACS ramp filters: FR656N at 6577A (6C0140+326, z = 4.41), FR656N at 6703A (RCJ0311+0507, z = 4.51), FR716N at 7148A (J1639+4052, z = 4.88), and FR782N at 7530A (TN J0924-2201, z = 5.197)", 3 orbit per source. The targets have total Lyalpha fluxes of the order of 10^-17 erg cm^-2 s^-1; the faintest is TN J0924-2201 at 2.1 x 10^-17 erg cm^-2 s^-1 (Venemans et al. 2004), which our 3-orbit ramp images will detect at S/N ~ 8-9 in total. At HST resolution this emission will be resolved into discrete knots and filaments, providing morphological information on the ionization structure unattainable from the ground. ETC simulations with 5x5 pixel rebinning confirm S/N ~ 3 at 8 x 10^-18 erg cm^-2 s^-1 for sources compact on scales <= 0.25" (<= 1.6 kpc at z ~ 4.5), sufficient to detect compact companion Lyalpha emitters comparable to those spectroscopically confirmed in the field of TN J0924-2201 by Venemans et al. (2004). The ETC for the broad-band filters confirm S/N > 5 for K(Vega) = 23.3 mag arcsec^-2 (~2 mag fainter than the targets) and K(Vega) = 24.3 for point sources. ACS observations use a 4-point dither pattern with exposure times set to ensure adequate sky background for pixel-based CTE correction. Post-flash will be used for the ramp filter. Dr. Marco Chiaberge is the PI or co-I of more than 20 HST programs mostly focused on AGN and is the lead of the HST-3C project on radio-loud AGN. He has first-authored more than 15 refereed papers based on HST data and is an expert in radio-loud and radio-quiet AGN, host galaxies, and large-scale environments. He has been leading for almost a decade the calibration of HST's Advanced Camera for Surveys at STScI. Prof. Colin Norman is an expert in theory and modelling of galaxy formation, active galactic nuclei and the multiphase gas dynamics of environmental feedback for the agn-galaxy connection. Professor George Miley is an expert on extragalactic radio sources. He has played a leading role in the discovery of the most distant radio sources, their association with protoclusters and studies of the interaction of radio jets with their host galaxies. Dr. Balmaverde works on the multiwavelength properties of radio galaxies, exploring the impact of the radio jets on the surrounding medium. She is the PI of the MUSE project "MURALES", a survey of 3CR radio galaxies with MUSE. Dr. Roberto Gilli is an expert in multi-band observations of AGN, and has worked extensively on their physics, large-to-small scale environment, and cosmic evolution. Dr. Massimo Stiavelli is a leading expert in high-redshift galaxy formation and the epoch of reionization. He has extensive experience with HST and JWST instrumentation and data analysis, having served as Mission Head for JWST at STScI. Dr. Alessandro Capetti has extensive expertise in radio-loud AGN, jet-host galaxy interactions, and HST imaging of AGN at low and intermediate redshifts. He is a long-standing collaborator on HST programs targeting radio galaxy morphology and environments. Dr. Paolo Tozzi has broad expertise in galaxy clusters, large-scale structure, and X-ray observations of high-redshift AGN and their environments. He contributes key expertise in the multiwavelength characterization of the proposal targets. Supermassive Black Holes and Active Galaxies 6 false false false false false false false true PRIMARY 14 true SUPPORTED GALAXY RADIO GALAXY This object was generated by the targetselector and retrieved from the NED database. J2000 J2000 K=19.9 GALAXY RADIO GALAXY This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 K=21.1 GALAXY RADIO GALAXY This object was generated by the targetselector and retrieved from the NED database. J2000 J2000 K=21.7 GALAXY RADIO GALAXY This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 F775W = 25.8 AB WFC3/IR Imaging No No F140W ACS/WFC Imaging No No F775W ACS/WFC RampFilter No No FR716N WFC3/IR Imaging No No F140W ACS/WFC Imaging No No F775W ACS/WFC RampFilter No No FR656N WFC3/IR Imaging No No F140W ACS/WFC Imaging No No F775W ACS/WFC RampFilter No No FR656N WFC3/IR Imaging No No F160W ACS/WFC RampFilter No No FR716N POS-TARG DITHER 0.2637 LINE false false 6 20.7 SPIRAL 2 false POS-TARG DITHER 0.572 LINE 0.365 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 3 false POS-TARG DITHER 3.034 LINE false false 4 85.29 ACS-WFC-DITHER-LINE 4 false The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "01" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1136896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "01" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2666 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2987 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "02" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1705344 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2598 :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 2987 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18425 :visit-id "02" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2516 :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 2987 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18425 :visit-id "02" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2496 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2987 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "03" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:07.0" :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 905248 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "03" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2624 :al-overhead-at-end 0 :internal-dur-at-end 671 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2987 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "04" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:08.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1136896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "04" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2666 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "05" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:08.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1705344 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "05" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2578 :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 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18425 :visit-id "05" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2536 :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 2977 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18425 :visit-id "05" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2496 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "06" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:09.0" :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 905248 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "06" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2624 :al-overhead-at-end 0 :internal-dur-at-end 671 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2977 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "07" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:09.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1136896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "07" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2666 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3001 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "08" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:10.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1705344 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "08" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2598 :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 3001 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18425 :visit-id "08" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2516 :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 3001 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18425 :visit-id "08" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2496 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3001 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "09" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:10.0" :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 905248 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "09" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2624 :al-overhead-at-end 0 :internal-dur-at-end 671 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3001 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "10" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:10.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1705344 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "10" :obset-id "10" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "10" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2598 :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 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18425 :visit-id "10" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2516 :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 2979 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18425 :visit-id "10" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2496 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 34.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18425 :visit-id "11" :proposal-version -1 :trans-version "20260618" :date "12-Aug-2026 11:57:11.0" :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 1810496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18425 :visit-id "11" :obset-id "11" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18425 :visit-id "11" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2562 :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 3001 :pcs-gap 0 ) (Tic-Orbit :proposal-id 18425 :visit-id "11" :orbit-number 2 :pcs-time 301 :si-vis-utilization 2542 :al-overhead-at-end 0 :internal-dur-at-end 690 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3001 :pcs-gap 0 ) true 2 0