17220( 4) - 26-Jun-2023 18:24:13 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17220 Version: 4 Check-in Time: 26-Jun-2023 18:24:13 STScI Edit Number: 0 Title Are There Two Classes of Lyman-Leaky Galaxies? ------------------------------------------------------------------------------------ Type Cycle GO 30 ------------------------------------------------------------------------------------ Investigators Contact? PI: Timothy M. Heckman The Johns Hopkins University Y CoI: Dr. Sanchayeeta Borthakur Arizona State University N CoI: Prof. John Chisholm University of Texas at Austin N CoI: Prof. Mauro Giavalisco University of Massachusetts - Amherst N CoI: Dr. Alaina L. Henry Space Telescope Science Institute N CoI: Prof. Anne Jaskot Williams College N CoI: Prof. Goeran Oestlin Stockholm University N CoI: Dr. Roderik Overzier Observatorio Nacional N CoI: Prof. Daniel Schaerer University of Geneva, Department of N Astronomy CoI: Dr. Zhiyuan Ji University of Arizona N CoI: Dr. Claus Leitherer Space Telescope Science Institute N CoI: Dr. Bingjie Wang The Pennsylvania State University N CoI: Dr. Xinfeng Xu The Johns Hopkins University N CoI: Prof. Matthew James Hayes Stockholm University N CoI: Ms. Sophia R Flury University of Massachusetts - Amherst N ------------------------------------------------------------------------------------ Abstract The largest uncertainty in understanding the Epoch of Reionization (EOR) concerns the physical processes that enable Lyman Continuum (LyC) photons to escape the ISM in EOR galaxies. In recent years there has been significant progress in finding leaky galaxies at both low (z < 0.4) and moderate (z ~ 3) redshifts. At low-z most of the known leaky galaxies are relatively low-mass galaxies hosting intense starbursts. However, there are now three examples at low-z that are dramatically different: they have relatively large stellar masses and SFRs and very compact sizes (leading extremely large values of SFR/Area). They are so disjoint in their properties from other low-z leaky galaxies that the physical processes that enable the LyC leakage are almost certainly different. Intruigingly, they are actually quite similar to known leaky galaxies at z ~ 3 in terms of mass and SFR. In this proposal we request time to observe five new potential members of this class of massive compact leaky starbursts, selected to have the same properties as the three currently-known examples. Our goals are to directly detect escaping LyC radiation, quantify its escape fraction, ascertain whether these galaxies show the other UV properties associated with leakiness, and improve our knowledge of their demographics. These galaxies can significantly broaden our horizons in understanding the full range of processes that enable the escape of LyC radiation. They may also represent the best local analogs to the most massive/luminous EOR galaxies, which may have 17220( 4) - 26-Jun-2023 18:24:13 - [ 2] been major contributors to reionization, and which will be the brightest EOR galaxies (allowing the most detailed studies with JWST). ------------------------------------------------------------------------------------ Observations Description ------------------------ Observing Description 1. Sample Selection We have used the SDSS DR12, GALEX-GR6, and WISE catalogs to identify galaxies meeting the following criteria: z > 0.25, stellar mass > 10^10 solar masses, strong [SII] deficiency, far-UV flux > 10^-16 erg cm^-2 s^-1 Ang^-1, and u-band half-light radius < 0.5 arcsec, no sign of an AGN. This results in a sample of 5 targets. 2. Observational Set-up We will aquire two types of data: We will perform COS target acquistion images using the standard near-UV imaging mode. This methofd produces the most reliable results for target centering in the COS primary science aperture (PSA), We will use the PSA MIRROR A mode. The images will be of sufficient quality for us to measure the size and structure of the starburst and assess the relationship between the escape of LyC radiation and starburst compactness and/or SFR/area. We will use the COS G140L 800 grating to collect data below the Lyman limit. 3. Required Exposure Times The exposure times were calculated uisng the on-line STScI COS Exposure Time Calculator. We first used the GALEX FUV and NUV fluxes to estimate a flux at 1000 (1+z) Ang. We corrected this for aperture effects by assuming that the relative flux inside the COS aperture to the total is the same as the same ratio derived from SDSS u--band images. This method has proved reliable in the past. G140L: The intrinsic amplitude of the Lyman break in the stellar population (no ISM) is typically a factor of 2 to 3. Our goal is to reach a relative escape fraction of 10% at a 3-sigma confidence level. This implies measuing the LyC at a flux level of 3 to 5% of the flux at 1000(1+z) Ang. These measurements will be made by smoothing the data and measuring the flux in a window extending from the Lyman break to roughlly 20 to 80 Ang blueward (depending on the redshift of the galaxy). Based on ETC simulations, the required exposure times require 2 to 4 orbits per galaxy. NUV ACQ Images: We have used the GALEX NUV fluxes and the SDSS u-band half-light radius. We aim for a total S/N of 40 to be able to accurately measure the NUV size. This implies exposure times of roughly 300 sec per target. ------------------------------------------------------------------------------------ 17220( 4) - 26-Jun-2023 18:24:13 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 J0121+0614 GALAXY, STARBURST RA=01H21M17.9000S +/- 0.1", J2000 V = 19.4 +/- 0.1 DEC=+06D14'56.90" +/- 0.1" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 2 J0219-0523 GALAXY, STARBURST RA=02H19M24.4800S +/- 0.1", J2000 V = 19.4 +/- 0.1 DEC=-05D23'35.20" +/- 0.1" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 3 J1145+3350 GALAXY, STARBURST RA=11H45M16.5000S +/- 0.1", J2000 V = 20.1 +/- 0.1 DEC=+33D50'51.70" +/- 0.1" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 4 J1230+3657 GALAXY, STARBURST RA=12H30M54.8600S +/- 0.1", J2000 V = 20.2 +/- 0.1 DEC=+36D57'20.20" +/- 0.1" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 5 J2338-0302 GALAXY, STARBURST RA=23H48M31.1000S +/- 0.1", J2000 V = 19.5 +/- 0.1 DEC=-03D02'41.00" +/- 0.1" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 17220( 4) - 26-Jun-2023 18:24:13 - [ 4] Visit: 01 (J0121+0614) Visit Requirements: 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 J0121+0614 COS/NUV ACQ/IMA PSA MIRRORA 1 300 S (300 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J0121+0614 COS/FUV TIME-TA PSA G140L 800 FP-POS=1, BUFFER-TIME=10000, 1 100 S G FLASH=YES see below (1802 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 J0121+0614 COS/FUV TIME-TA PSA G140L 800 FP-POS=2, BUFFER-TIME=10000, 1 2469 S G FLASH=YES see below (2689 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 J0121+0614 COS/FUV TIME-TA PSA G140L 800 FP-POS=3, BUFFER-TIME=10000, 1 2469 S G FLASH=YES see below (2689 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 J0121+0614 COS/FUV TIME-TA PSA G140L 800 FP-POS=4, BUFFER-TIME=10000, 1 2469 S G FLASH=YES see below (2689 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 | ------------------------------------------------------------------------------------------------------------------------------------ J0121+0614 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE J0121+0614 2 COS/FUV TIME-TA PSA G140L 800 none none none none 1 1802.0 S G J0121+0614 3 COS/FUV TIME-TA PSA G140L 800 none none none none 2 2689.0 S G J0121+0614 4 COS/FUV TIME-TA PSA G140L 800 none none none none 3 2689.0 S G J0121+0614 5 COS/FUV TIME-TA PSA G140L 800 none none none none 4 2689.0 S G 17220( 4) - 26-Jun-2023 18:24:13 - [ 5] Visit: 02 (J0219--0523) Visit Requirements: 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 J0219-0523 COS/NUV ACQ/IMA PSA MIRRORA 1 300 S (300 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J0219-0523 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=1, 1 1800 S G FLASH=YES (1800 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 J0219-0523 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=4, 1 2500 S G FLASH=YES see below (2689 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 | ------------------------------------------------------------------------------------------------------------------------------------ J0219-0523 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE J0219-0523 2 COS/FUV TIME-TA PSA G140L 800 none none none none 1 N/A G J0219-0523 3 COS/FUV TIME-TA PSA G140L 800 none none none none 2 2689.0 S G 17220( 4) - 26-Jun-2023 18:24:13 - [ 6] Visit: 03 (J1145+33) Visit Requirements: 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 J1145+3350 COS/NUV ACQ/IMA PSA MIRRORA 1 300 S (300 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J1145+3350 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=1, 1 1600 S G FLASH=YES see below (1837 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 J1145+3350 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=4, 1 2700 S G FLASH=YES see below (2724 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 | ------------------------------------------------------------------------------------------------------------------------------------ J1145+3350 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE J1145+3350 2 COS/FUV TIME-TA PSA G140L 800 none none none none 1 1837.0 S G J1145+3350 3 COS/FUV TIME-TA PSA G140L 800 none none none none 2 2724.0 S G 17220( 4) - 26-Jun-2023 18:24:13 - [ 7] Visit: 04 (J1230+3657) Visit Requirements: 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 J1230+3657 COS/NUV ACQ/IMA PSA MIRRORA 1 300 S (300 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J1230+3657 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=1, 1 1600 S G FLASH=YES see below (1857 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 J1230+3657 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=4, 1 3000 S G FLASH=YES see below (2744 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 | ------------------------------------------------------------------------------------------------------------------------------------ J1230+3657 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE J1230+3657 2 COS/FUV TIME-TA PSA G140L 800 none none none none 1 1857.0 S G J1230+3657 3 COS/FUV TIME-TA PSA G140L 800 none none none none 2 2744.0 S G 17220( 4) - 26-Jun-2023 18:24:13 - [ 8] Visit: 05 (J2348-03) Visit Requirements: 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 J2338-0302 COS/NUV ACQ/IMA PSA MIRRORA 1 300 S (300 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J2338-0302 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=1, 1 1500 S G FLASH=YES see below (1799 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 J2338-0302 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=4, 1 3000 S G FLASH=YES see below (2686 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 | ------------------------------------------------------------------------------------------------------------------------------------ J2338-0302 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE J2338-0302 2 COS/FUV TIME-TA PSA G140L 800 none none none none 1 1799.0 S G J2338-0302 3 COS/FUV TIME-TA PSA G140L 800 none none none none 2 2686.0 S G 17220( 4) - 26-Jun-2023 18:24:13 - [ 9] Visit: 06 (Re-do of visit 5) Visit Requirements: On Hold Comments: Additional Comments: HOPR filed for guide star acquistion failure at start of orbit 2 for visit 5. 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 J2338-0302 COS/NUV ACQ/IMA PSA MIRRORA 1 300 S (300 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J2338-0302 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=4 1 1799 S G (1799 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 | ------------------------------------------------------------------------------------------------------------------------------------ J2338-0302 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE J2338-0302 2 COS/FUV TIME-TA PSA G140L 800 none none none none 1 N/A G 17220( 4) - 26-Jun-2023 18:24:13 - [ 10] Visit: 07 (Redo of visit 2) Visit Requirements: On Hold Comments: Additional Comments: Guide star acquistion failed before start of orbit 2. HOPR filed. 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 J0219-0523 COS/NUV ACQ/IMA PSA MIRRORA 1 300 S (300 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 J0219-0523 COS/FUV TIME-TA PSA G140L 800 BUFFER-TIME=10000, FP-POS=4 1 1800 S G (1800 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 | ------------------------------------------------------------------------------------------------------------------------------------ J0219-0523 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE J0219-0523 2 COS/FUV TIME-TA PSA G140L 800 none none none none 1 N/A G 17220( 4) - 26-Jun-2023 18:24:13 - [ 11] Summary Form for Proposal 17220 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=10000, FLASH=YES, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names J0121+0614, J0219-0523, J1145+3350, J1230+3657, J2338-0302 ------------------------------------------------------------------------------------------------------------------------------------