Assigned ID: 988 ----- Attempting Submission 1 (Sat Feb 27 00:53:21 GMT 2010) ----- HST Phase I Proposal 988 (AQuider_HSTCYC18.apt) successfully submitted. Brian Siana made Contact CoI ----- Attempting Submission 1 (Wed Jul 07 14:23:15 GMT 2010) ----- HST Phase II Proposal 12266 (AQuider_HSTCYC18.apt) successfully submitted. ----- Attempting Submission 2 (Fri Oct 01 12:36:50 GMT 2010) ----- ----- Attempting Submission 3 (Tue Aug 02 18:07:28 GMT 2011) ----- Will be processed in-house Lyman Continuum Escape Fractions with a Lensed LBG in the 'Sweet Spot' We propose to search for Lyman continuum (LyC) emission from the Cosmic Horseshoe. This star-forming galaxy at z = 2.38115 has been strongly lensed into a nearly complete Einstein ring of 10 arcsec diameter and magnified by a factor of 25 to g=20.1. The Cosmic Horseshoe is an ideal candidate for finding escaping LyC photons and studying in detail how LyC emission happens within a galaxy. In previous work we have shown that this galaxy has gaps in its interstellar medium, which are strongly correlated with a high escape fraction of LyC photons. We will improve the sensitivity of LyC escape fraction measurements by over an order of magnitude, thanks to the flux and resolution boost from gravitational lensing and the fortuitous location of the HST/UVIS F275W filter in the 'sweet spot' just redward of the Lyman limit. We will probe LyC escape fractions down to <3% at the 3-sigma level and constrain LyC emission across hundreds of resolution elements, corresponding to galactic structures as small as 100 pc. This galaxy has been well-characterized by studies in multiple wavebands, allowing us to place the LyC emission into the broader context of the Cosmic Horseshoe's properties. These HST observations will allow us to constrain how LyC emission happens within this galaxy and will guide our understanding of cosmic reionization.
We have received 10 orbits and will conduct our observations with HST/UVIS+F275W in a four point box dither pattern and a two point line dither pattern with sub-pixel dithering to better sample the point spread function (PSF). As our observations will be read noise limited, we will take long exposures of half of an orbit per exposure. We will execute two visits of five orbits each, with each visit completing two four-point box dither patterns and a two-point line dither pattern. COSMOLOGY 12 false 0.0 0.0 false false false false SUPPORTED GALAXY EINSTEIN RING GRAVITATIONAL LENS HIGH REDSHIFT GALAXY COSMIC-HORSESHOE J2000 J2000 u=21.6, g=20.1, i=19.7, E(B-V)=0.15 WFC3/UVIS Imaging No No F275W POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 1 false POS-TARG DITHER 0.145 LINE false false 2 46.84 WFC3-UVIS-DITHER-LINE 2 false /private/var/folders/U7/U7EpVZ9NHJe91f-zXie+mk++4y2/-Tmp-/OPVisit5314376697988150802.xml The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12266 :visit-id "01" :proposal-version -1 :trans-version "20110509" :date "02-Aug-2011 14:05:31.0" :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 12266 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12266 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2856 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12266 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2966 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12266 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2966 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12266 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2966 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12266 :visit-id "01" :orbit-number 5 :pcs-time 222 :si-vis-utilization 2966 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) true 5 0 /private/var/folders/U7/U7EpVZ9NHJe91f-zXie+mk++4y2/-Tmp-/OPVisit7857536159119033638.xml The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12266 :visit-id "02" :proposal-version -1 :trans-version "20110509" :date "02-Aug-2011 14:05:33.0" :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 12266 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12266 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2856 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12266 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2966 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12266 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2966 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12266 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2966 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12266 :visit-id "02" :orbit-number 5 :pcs-time 222 :si-vis-utilization 2966 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) true 5 0