16733( 3) - 07-Jan-2022 21:30:03 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16733 Version: 3 Check-in Time: 07-Jan-2022 21:30:03 STScI Edit Number: 0 Title Mapping the escape of Ly alpha and ionizing photons from an extreme emission-line lensed galaxy ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jane R. Rigby NASA Goddard Space Flight Center Y CoI: Dr. Keunho J. Kim University of Cincinnati Main Campus N CoI: Dr. Matthew Bayliss University of Cincinnati Main Campus N CoI: Dr. Michael Florian University of Arizona N CoI: Prof. Michael D. Gladders University of Chicago N CoI: Prof. Keren Sharon University of Michigan N CoI: Dr. T. Emil Rivera-Thorsen Stockholm University N CoI: Dr. Ramesh Mainali NASA Goddard Space Flight Center N CoI: Dr. John Chisholm University of Texas at Austin N CoI: Michelle Berg University of Texas at Austin N CoI: Dr. Guillaume Mahler Durham Univ. N ------------------------------------------------------------------------------------ Abstract We propose 10 orbits of HST WFC3-UVIS G280 slitless grism spectroscopy of S1723, an extremely bright gravitationally lensed galaxy at redshift z=1.3293. The proposed observations will spatially map Lyman alpha, escaping ionizing radiation, and the non-ionizing UV spectral slope, on spatial scales never before obtained for an extreme emission line galaxy. Combining this new spectrum with a published HST-WFC3 G141 grism of Ha will produce maps of Lya escape fraction and ionizing photon escape fraction, to reveal how Lyman alpha and ionizing photons are able to escape. This target has the extremely strong rest-frame UV and optical emission lines that are a hallmark of galaxies at the epoch of reionization (z~7--8), but due to lensing magnification, can be studied at very high spatial resolution. The target has a wealth of published data including HST multiband imaging, a lens model, and MMT, Keck, Gemini, and HST spectra, and is an approved target for JWST imaging and spectroscopy with NIRCam, NIRSpec, and MIRI, with all data to go public as they are observed. ------------------------------------------------------------------------------------ Observations Description ------------------------ This is 10 orbits of WFC3/UVIS grism spectroscopy, using the G280 grism, with just enough direct imaging in F300X to do the wavelength calibration. We adapted the observing strategy from the similar program GO 15966. We split the 10 orbits into 3 visits (3 orbits, 3 orbits, 4 orbits) to improve schedulability. As noted in Phase 1, we request an ORIENT special requirement to avoid bright contaminating sources, especially the brightest cluster galaxy, and to place the arc as perpedicular as possible to the dispersion direction (to minimize the extent to which the arc contaminates itself). We find that there is one 16733( 3) - 07-Jan-2022 21:30:03 - [ 2] unique ORIENT, as well as its +180 degree sister, that satisfies these contamination issues. We chose this ORIENT using Aladin. As suggested by our Instrument Scientist, we use a postflash to set a minimum UVIS image total background of ~20 electrons/pix (actually 19.9). ------------------------------------------------------------------------------------ 16733( 3) - 07-Jan-2022 21:30:03 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1723+34 GALAXY, EMISSION LINE RA=17H23M36.4060S, J2000 V = 20.5 +/- 0.1 From Florian et al. 11 NEBULA, GRAVITATIONAL DEC=+34D11'54.69" 2021: m_(1.6um)=20.1, m(1.4um)=20.2, LENS, HIGH REDSHIFT m(1.1um)=20.2, m(1.05um)=19.9, GALAXY, STAR FORMING m(0.775um)=20.5, m(0.390um)=20.6. All REGION AB mags Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 16733( 3) - 07-Jan-2022 21:30:03 - [ 4] Visit: 01 (S1723-rollA-1) Visit Requirements: ORIENT 129D TO 129 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1723+3 WFC3/UVI ACCUM G280-REF F300X FLASH=19, CR-SPLIT=2 1 400 S (400 POS TARG null, -50 411 S S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2105 S POS TARG null, -50 411 S (2105 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2780 S POS TARG null, -50 411 S (2780 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ1723+3411 1 WFC3/UVI ACCUM G280-REF F300X none none none 1 1 N/A S SDSSJ1723+3411 1 WFC3/UVI ACCUM G280-REF F300X none none none 2 1 N/A S SDSSJ1723+3411 2 WFC3/UVI ACCUM UVIS G280 none none none none 1 N/A S SDSSJ1723+3411 3 WFC3/UVI ACCUM UVIS G280 none none none none 2 N/A S 16733( 3) - 07-Jan-2022 21:30:03 - [ 5] Visit: 02 (S1723-rollA-2) Visit Requirements: ORIENT 129D TO 129 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1723+3 WFC3/UVI ACCUM G280-REF F300X FLASH=19, CR-SPLIT=2 1 400 S (400 POS TARG -0.092, -50.098 411 S S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2105 S POS TARG -0.092, -50.098 411 S (2105 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2780 S POS TARG -0.092, -50.098 411 S (2780 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2780 S POS TARG -0.092, -50.098 411 S (2780 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ1723+3411 1 WFC3/UVI ACCUM G280-REF F300X none none none 1 1 N/A S SDSSJ1723+3411 1 WFC3/UVI ACCUM G280-REF F300X none none none 2 1 N/A S SDSSJ1723+3411 2 WFC3/UVI ACCUM UVIS G280 none none none none 1 N/A S SDSSJ1723+3411 3 WFC3/UVI ACCUM UVIS G280 none none none none 2 N/A S SDSSJ1723+3411 4 WFC3/UVI ACCUM UVIS G280 none none none none 3 N/A S 16733( 3) - 07-Jan-2022 21:30:03 - [ 6] Visit: 03 (S1723-rollB-1) Visit Requirements: ORIENT 309D TO 309 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1723+3 WFC3/UVI ACCUM G280-REF F300X FLASH=19, CR-SPLIT=2 1 400 S (400 POS TARG null, -50 411 S S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2105 S POS TARG null, -50 411 S (2105 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2780 S POS TARG null, -50 411 S (2780 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ1723+3411 1 WFC3/UVI ACCUM G280-REF F300X none none none 1 1 N/A S SDSSJ1723+3411 1 WFC3/UVI ACCUM G280-REF F300X none none none 2 1 N/A S SDSSJ1723+3411 2 WFC3/UVI ACCUM UVIS G280 none none none none 1 N/A S SDSSJ1723+3411 3 WFC3/UVI ACCUM UVIS G280 none none none none 2 N/A S 16733( 3) - 07-Jan-2022 21:30:03 - [ 7] Visit: 04 (S1723-rollB-2) Visit Requirements: ORIENT 309D TO 309 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSSJ1723+3 WFC3/UVI ACCUM G280-REF F300X FLASH=19, CR-SPLIT=2 1 400 S (400 POS TARG -0.092, -50.098 411 S S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2105 S POS TARG -0.092, -50.098 411 S (2105 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2780 S POS TARG -0.092, -50.098 411 S (2780 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSSJ1723+3 WFC3/UVI ACCUM UVIS G280 1 2780 S POS TARG -0.092, -50.098 411 S (2780 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSSJ1723+3411 1 WFC3/UVI ACCUM G280-REF F300X none none none 1 1 N/A S SDSSJ1723+3411 1 WFC3/UVI ACCUM G280-REF F300X none none none 2 1 N/A S SDSSJ1723+3411 2 WFC3/UVI ACCUM UVIS G280 none none none none 1 N/A S SDSSJ1723+3411 3 WFC3/UVI ACCUM UVIS G280 none none none none 2 N/A S SDSSJ1723+3411 4 WFC3/UVI ACCUM UVIS G280 none none none none 3 N/A S 16733( 3) - 07-Jan-2022 21:30:03 - [ 8] Summary Form for Proposal 16733 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures G280-REF, UVIS ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2, FLASH=19 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 129D TO 129 D, ORIENT 309D TO 309 D, POS TARG -0.092, -50.098, POS TARG null, -50 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F300X, G280 ------------------------------------------------------------------------------------------------------------------------------------ Target Names SDSSJ1723+3411 ------------------------------------------------------------------------------------------------------------------------------------