0 Assigned ID: 3834 ----- Attempting Submission 1 (Fri Oct 21 13:57:39 GMT 2022) ----- POS TARG & PATTERN should be used carefully with ACS ramp filters as central wavelengths & transmission efficiencies vary within the apertures. 0 ----- Attempting Submission 1 (Fri Dec 16 15:26:35 GMT 2022) ----- ----- Attempting Submission 2 (Mon Jan 30 08:55:12 GMT 2023) ----- NA Unveiling the origin and nature of the UV-brightest Lyman continuum emitting star-forming galaxy J1316+2614 at z=3.613 was recently discovered as the UV-brightest star-forming galaxy and also the strongest Lyman continuum (LyC, with energies >13.6 eV) emitter ever detected. 1316+2614 also shows other outstanding properties, including possible "exotic" stellar populations and massive inflowing gas, hinting at a new, very efficient mode of star formation. These unexpected results challenge our understanding of the LyC escape in UV-bright galaxies, and of the potential role these sources may play in cosmic reionization. Furthermore, unsually bright galaxies are now being discovered at very high-redshifts with the James Webb, stressing the need to urgently understand the nature of such sources. The exceptional properties of J1316+2614 call for rapid follow-up observations. Here we request Hubble Space Telescope high-resolution imaging of J1316+2614 for the morphological characterization of the LyC emitting regions, ionizing source, inflowing gas, and the elusive old stellar population. The requested observations will uncover some of the most important, but still open questions raised by this exceptional source, including those related to its origin and nature. This program uses four different filters to obtain rest-frame UV emission (ionizing and non-ionizing emission with the WFC3/UVIS F410M and F775W filters, respectively), map the LyA emission (with the ACS/WFC ramp filter FR551N), and rest-optical emission (WFC3/IR F160W) of a bright Lyman continuum emitter at z=3.613. F410M observations (2 orbits, 1 visit) use a dither-line pattern with 6 points for cosmic rays removal. A post-flash of 14e- is required to reach a sufficient background level. For F775W (1 orbit) we use the standard 4-point box pattern. F775W requires a post-flash of 6e- due to 4 exposures in the 1 orbit to obtain a very clean image. FR551N (1 orbit) uses a standard 4-point box pattern, but no post-flash is required in this case. The central wavelength of FR551N is set to 5604\AA (LyA emission at z=3.613). F160W (1 orbit) uses also the standard 4-point box pattern. For WFC3/UVIS F775W, the target is placed at Aperture='UVIS'. For WFC3/UVIS F410M the target is placed at Aperture='UVIS-C1K1C-CTE' with a specific orient range to avoid placing a bright star on the detector.For WFC3/IR F160W we use Aperture='IR' without any special requirement for orientation. The team has all the experience, tools, and background to successfully carry out the proposed project. The PI has led the discovery work of the target of this proposal. Our team has also experience on similar observational studies, leading as PIs several HST campaigns to observe LyC and UV emission of star-forming galaxies. In particular, the team has experience in the scientific topics of this proposal, including: -LyC emission and measurements: Marques-Chaves, Chisholm, Schaerer -Stellar population modeling including VMS: Schaerer, Chisholm Upadhyaya -Extended Lyman-alpha emission: Leclercq, Schaerer, Chisholm Finally, the PI and Co-I dispose of other ancillary observations of this target, including ALMA observations of the dust emission and molecular gas, VLT/XShooter high-resolution spectra, and Keck/KCWI IFU observations. Galaxies 3 false false false false false true false SUPPORTED GALAXY HIGH REDSHIFT GALAXY J2000 J2000 R=21.2 WFC3/UVIS Imaging No No F410M WFC3/UVIS Imaging No No F775W ACS/WFC RampFilter No No FR551N WFC3/IR Imaging No No F160W POS-TARG DITHER 0.145 LINE false false 6 46.84 WFC3-UVIS-DITHER-LINE 1 false POS-TARG DITHER 0.2637 LINE 0.1856 false false 69.02 4 20.7 ACS-WFC-DITHER-BOX 2 false POS-TARG DITHER 1.5 LINE 1.5 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 4 false POS-TARG DITHER 1.75 LINE 1.75 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 3 false The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17286 :visit-id "01" :proposal-version -1 :trans-version "20220630" :date "29-Jan-2023 21:28:16.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1732464 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17286 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17286 :visit-id "01" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2772 :al-overhead-at-end 119 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3165 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17286 :visit-id "01" :orbit-number 2 :pcs-time 392 :si-vis-utilization 2772 :al-overhead-at-end 119 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3165 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17286 :visit-id "03" :proposal-version -1 :trans-version "20220630" :date "16-Dec-2022 16:19:14.0" :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 17286 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17286 :visit-id "03" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2782 :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 3165 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17286 :visit-id "04" :proposal-version -1 :trans-version "20220630" :date "16-Dec-2022 16:19:15.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17286 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17286 :visit-id "04" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2779 :al-overhead-at-end 121 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3165 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17286 :visit-id "05" :proposal-version -1 :trans-version "20220630" :date "30-Jan-2023 09:54:13.0" :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 974896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17286 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17286 :visit-id "05" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2646 :al-overhead-at-end 0 :internal-dur-at-end 481 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3165 :pcs-gap 0 ) true 1 0