0 Assigned ID: 932 ----- Attempting Submission 1 (Fri Apr 08 22:42:31 GMT 2016) ----- 0 ----- Attempting Submission 1 (Wed Jul 20 16:55:12 GMT 2016) ----- Lyman-alpha Imaging at ~20 pc Resolution in a Low Mass Lensed Galaxy at z=1.85 Because Lyman-alpha photons are resonantly scattered by neutral hydrogen, the strength and spatial extent of Lya emission in galaxies depend on the HI column density and covering fraction, properties that are of primary interest to the escape of ionizing radiation. Lya emission is particularly important to the study of low mass, low metallicity galaxies: such objects are likely to be responsible for the reionization of the universe, and Lya emission is more common in these galaxies. With this proposal, we request 7 orbits of WFC3/UVIS imaging to obtain a high resolution map of Lya emission in the low mass, low metallicity z=1.85 gravitationally lensed galaxy SL2SJ021737-051329. With oxygen abundance <10% of solar, stellar mass <10^8 Msun, and extremely strong Lya emission with rest-frame equivalent width ~120 A, this object is a prime example of a low mass Lya-emitter, and its gravitational magnification by a factor of ~35 results in remarkably high WFC3/UVIS spatial resolution of ~20 pc. Existing HST broadband and IR grism observations will allow us to compare the spatial extent of the Lya emission with both the rest-frame UV continuum and the rest-frame optical nebular line emission, in order to map the resonant scattering of Lya photons from their origin in star-forming regions, obtain constraints on the location of the scattering gas, and relate this information to the kinematics and geometry of the galaxy. The proposed observations, in combination with the spectroscopic information we have already obtained, will provide the most comprehensive and highest resolution picture of Lya emission at z > 1 to date. The goal of this proposal is to obtain a narrow-band Lya image of a gravitationally lensed galaxy at z=1.85 using the WFC3 UVIS F343N filter. We will observe the galaxy in the F343N filter for 6 orbits, and in the F390M filter for 1 orbit in order to obtain an off-line continuum image. For all observations we use the UVIS-C1K1C-CTE aperture in order to place the target near one of the amplifiers in order to minimize CTE effects. Observations are divided into 4 visits. Visits 1-3 are identical and contain the F343N observations, with 2 orbits per visit. We use the WFC3-UVIS-DITHER-LINE pattern for two exposures per orbit, and include 10 e- FLASH based on the expectation of ~2 e- from sky+dark in ~1400 sec. Visit 4 contains the F390M observations. We again use the WFC3-UVIS-DITHER-LINE pattern for two exposures per orbit. We include 9 e- FLASH based on the expectation of ~3 e- from sky+dark in ~1400 sec. All visits are constrained to have the same ORIENT (SAME ORIENT AS Visit 01) in order to maximize image alignment and overlap between exposures for image registration. Galaxies 12 false false false false false false SUPPORTED GALAXY ELLIPTICAL GRAVITATIONAL LENS HIGH REDSHIFT GALAXY J2000 J2000 WFC3/UVIS Imaging No No F343N WFC3/UVIS Imaging No No F390M POS-TARG DITHER 0.145 LINE false false 2 46.84 WFC3-UVIS-DITHER-LINE 1 false Hst Same orient constraint links visits (01 02 03 04) The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. 1478949628000 14.993009999999998 (Tic-Visit :proposal-id 14632 :visit-id "01" :proposal-version -1 :trans-version "20160601" :date "20-Jul-2016 10:33:55.0" :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 1154976 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14632 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14632 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2880 :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 3213 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14632 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2990 :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 3213 :pcs-gap 0 ) false 2 0 Hst Same orient constraint links visits (01 02 03 04) The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. 1478783683000 14.993009999999998 (Tic-Visit :proposal-id 14632 :visit-id "02" :proposal-version -1 :trans-version "20160601" :date "20-Jul-2016 10:22:02.0" :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 1154976 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14632 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14632 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2880 :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 3213 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14632 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2990 :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 3213 :pcs-gap 0 ) false 2 0 Hst Same orient constraint links visits (01 02 03 04) The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. 1479035466000 14.993009999999998 (Tic-Visit :proposal-id 14632 :visit-id "03" :proposal-version -1 :trans-version "20160601" :date "20-Jul-2016 10:22:00.0" :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 1154976 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14632 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14632 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2880 :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 3213 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14632 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2990 :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 3213 :pcs-gap 0 ) false 2 0 Hst Same orient constraint links visits (01 02 03 04) The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. 1478869516000 14.993009999999998 (Tic-Visit :proposal-id 14632 :visit-id "04" :proposal-version -1 :trans-version "20160601" :date "20-Jul-2016 10:21:56.0" :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 577488 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14632 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14632 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2880 :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 3213 :pcs-gap 0 ) false 1 0 /solaris/user1/williamj/hst/work/cycle24/OP-cache/14632-v52.xml (Tic-Visit :proposal-id 14632 :visit-id "52" :proposal-version -1 :trans-version "20160601" :date "18-Nov-2016 08:01:01.0" :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 1154976 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14632 :visit-id "52" :obset-id "52" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14632 :visit-id "52" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2880 :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 3213 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14632 :visit-id "52" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2990 :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 3213 :pcs-gap 0 ) false 2 0