Added POS TARGs to visits 01 and 02 as suggested during Science Review. Submitted by PC Tricia Royle on behalf of PI Alice Shipley. -52231327 ----- Attempting Submission 3 (Tue Jan 15 14:59:53 GMT 2013) ----- Will be fully processed in-house Escaping Lyman-continuum (LyC) radiation from star-forming galaxies is likely responsible for the reionization of the universe. However, the direct measurement of escaping LyC radiation has proven exceptionally challenging. Recent spectroscopic and imaging detections of LyC emission from z~3 galaxies have revealed unexpectedly high values for the escape fraction of LyC photons, as well as spatial offsets between the apparent LyC emission and non-ionizing UV continuum. These results may indicate the processes governing the production and escape of LyC photons from distant star-forming galaxies, but may also signify contamination by low-redshift interlopers near the line of sight. We have obtained ultra-deep ground-based data probing the LyC region at z~2.85 in the Q1549+19 field. Our sample includes both spectroscopically confirmed Lyman Break Galaxies (LBGs) and Lyman-Alpha Emitters (LAEs), with 24 apparent detections of LyC radiation. However, without high spatial resolution redshift estimates for the specific regions associated with apparent LyC emission in the vicinity of LBGs and LAEs, our interpretation of these intriguing sources is fundamentally limited. Spatially-resolved photometric redshifts based on multi-band HST imaging represents the most effective path forward. Here we propose for 32 orbits of deep WFC3/F336W, ACS/F606W, WFC3/F125W, and WFC3/160W observations in two pointings covering the majority of our apparent LyC detections. Analysis of these data will robustly remove contamination from low-redshift interlopers, and reveal the processes through which galaxies reionized the universe and maintained the ionizing background. Pointings and Sample: We propose deep WFC3/UVIS/F336W (U), ACS/F606W (V), WFC3/IR/F125W (J), and WFC3/IR/F160W (H) imaging of two pointings in the Q1549+19 field containing a sample of 15 star-forming LBGs and LAEs at z~2.85 with apparent LyC detections. Our primary goal is to estimate robust photometric redshifts for all morphological subcomponents associated with NB3420 detections, and therefore obtain a clean sample of high-redshift LyC detections with detailed stellar population information. As described below, deep multi-band imaging with the proposed filter set will result in robust photometric redshifts, removal of low-redshift contaminants associated with NB3420 detections, and dissection of the nature of the apparent LyC emission. Furthermore, with a large set of NB3420 non-detections at $z\sim 2.85$ imaged by HST within the same pointings, we will conduct a differential comparison between the spatially-resolved stellar populations of objects with and without leaking LyC emission. ORIENT Strategy: As our z~3 targets are distributed across each pointing, the allowed range of ORIENT angles that enables the maximum number of targets is fairly constrained. For each visit, we specify the range of allowed ORIENT angles, which optimizes the number of targets covered. Orbit / Visit Strategy: Each F336W pointing is executed in a 5-orbit visit, broken down into 10 roughly half-orbit exposures. Each F606W pointing is executed in a 5-orbit visit, broken down into 5 single-orbit, 4-exposure dither patterns. Each IR (F125W or F160W) pointing is executed in a 3-orbit visit, broken into 3 single-orbit, 4-exposure dither patterns. The proposed program requires 32 orbits (2x5 orbits in F336W, 2x5 orbits in F606W, 2x3 orbits in F125W, and 2x3 orbits in F160W). Dither Strategy: The 10 exposures for each F336W visit are executed as a set of 2 WFC3-UVIS-DITHER-BOX patterns, followed by a single WFC3-UVIS-DITHER-LINE pattern. The 20 exposures for each F606W visit are executed as a set of 5, 4-point ACS-WFC-DITHER-BOX patterns. The 12 exposures for each WFC3/IR orbit (F125W and F160W) are executed as a set of 3, 4-point WFC3-IR-DITHER-LINE patterns. For both WFC3/IR and WFC3/UVIS observations, we use apply POS-TARG offsets between each dither pattern to improve the PSF sampling, and reduce the effects of bad pixels and droplets. Special Concerns: To mitigate CTE losses in our WFC3/UVIS/F336W exposures, we are using the "post-flash" capability, with FLASH=8. UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE 12 false 0.0 0.0 false false false false SUPPORTED GALAXY HIGH REDSHIFT GALAXY J2000 J2000 GALAXY HIGH REDSHIFT GALAXY J2000 J2000 GALAXY HIGH REDSHIFT GALAXY J2000 J2000 GALAXY HIGH REDSHIFT GALAXY J2000 J2000 GALAXY HIGH REDSHIFT GALAXY J2000 J2000 GALAXY HIGH REDSHIFT GALAXY J2000 J2000 ACS/WFC Imaging No No F606W ACS/WFC Imaging No No F606W WFC3/UVIS Imaging No No F336W WFC3/UVIS Imaging No No F336W WFC3/IR Imaging No No F125W WFC3/IR Imaging No No F125W WFC3/IR Imaging No No F160W WFC3/IR Imaging No No F160W POS-TARG DITHER 0.636 LINE false false 4 41.788 WFC3-IR-DITHER-LINE 2 false POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 3 false POS-TARG DITHER 0.265 LINE 0.187 false false 69.05 4 20.67 ACS-WFC-DITHER-BOX 4 false POS-TARG DITHER 0.145 LINE false false 2 46.84 WFC3-UVIS-DITHER-LINE 5 false The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. /private/var/folders/U7/U7EpVZ9NHJe91f-zXie+mk++4y2/-Tmp-/OPVisit6320168496397576709.xml 1358261878200 (Tic-Visit :proposal-id 12959 :visit-id "01" :proposal-version -1 :trans-version "20121031" :date "15-Jan-2013 09:57:56.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 5684480 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12959 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12959 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2910 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3020 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3020 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3020 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "01" :orbit-number 5 :pcs-time 222 :si-vis-utilization 3020 :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 3244 :pcs-gap 0 ) true 5 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. /private/var/folders/U7/U7EpVZ9NHJe91f-zXie+mk++4y2/-Tmp-/OPVisit1421162671705466931.xml 1358261870286 (Tic-Visit :proposal-id 12959 :visit-id "02" :proposal-version -1 :trans-version "20121031" :date "15-Jan-2013 09:57:48.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 5684480 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12959 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12959 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2910 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3020 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3020 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3020 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "02" :orbit-number 5 :pcs-time 222 :si-vis-utilization 3020 :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 3244 :pcs-gap 0 ) true 5 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12959 :visit-id "03" :proposal-version -1 :trans-version "20120604" :date "09-Jul-2012 18:41:51.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 3133584 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12959 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12959 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2840 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2840 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2840 :al-overhead-at-end 0 :internal-dur-at-end 614 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12959 :visit-id "04" :proposal-version -1 :trans-version "20120604" :date "09-Jul-2012 18:42:18.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 3133584 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12959 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12959 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2840 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "04" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2840 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "04" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2840 :al-overhead-at-end 0 :internal-dur-at-end 614 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. 1356118956000 321.0 (Tic-Visit :proposal-id 12959 :visit-id "05" :proposal-version -1 :trans-version "20120604" :date "09-Jul-2012 22:45:41.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 3133584 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12959 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12959 :visit-id "05" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2840 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "05" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2840 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "05" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2840 :al-overhead-at-end 0 :internal-dur-at-end 614 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. 1356205653000 321.0 (Tic-Visit :proposal-id 12959 :visit-id "06" :proposal-version -1 :trans-version "20120604" :date "08-Jul-2012 22:07:48.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 3133584 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12959 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12959 :visit-id "06" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2840 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "06" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2840 :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 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "06" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2840 :al-overhead-at-end 0 :internal-dur-at-end 614 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12959 :visit-id "07" :proposal-version -1 :trans-version "20120604" :date "09-Jul-2012 18:26:58.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2887440 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12959 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12959 :visit-id "07" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2910 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "07" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2910 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "07" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3022 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "07" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3022 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "07" :orbit-number 5 :pcs-time 222 :si-vis-utilization 3022 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 5 0 The scheduling data was generated by CASM 20.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12959 :visit-id "08" :proposal-version -1 :trans-version "20120604" :date "09-Jul-2012 18:27:00.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2887440 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12959 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12959 :visit-id "08" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2910 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "08" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2910 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "08" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3022 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "08" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3022 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12959 :visit-id "08" :orbit-number 5 :pcs-time 222 :si-vis-utilization 3022 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3244 :pcs-gap 0 ) true 5 0