15950( 4) - 29-Aug-2019 21:22:31 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15950 Version: 4 Check-in Time: 29-Aug-2019 21:22:31 STScI Edit Number: 1 Title 2MASS J13260399+7023462: One of the Most Luminous Quasars in the Universe? ------------------------------------------------------------------------------------ Type Cycle GO 27 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Anthony Hernan Gonzalez University of Florida Y CoI: Mr. Sarik Jeram University of Florida N CoI: Prof. Stephen S. Eikenberry University of Florida N ------------------------------------------------------------------------------------ Abstract We request a single orbit of WFC3 imaging to discern whether the recently discovered quasar 2MASS J13260399+7023462 (z=2.88) is one of the most ultraluminous quasars in the Universe, or is instead a strongly-lensed system that is unresolved in ground-based and Gaia imaging. If the quasar remains unresolved at HST/WFC3 resolution, this will exclude lensing for plausible foreground lens masses. If it is resolved, then these observations will enable us to model the lens system and constrain the magnification. This quasar is physically interesting in either scenario -- for probing the bright tail of the QSO luminosity function if unlensed, or else for enabling future lensing-based programs, such as probing the foreground IGM on small scales. ------------------------------------------------------------------------------------ Observations Description ------------------------ Given the brightness of this quasar, the primary concern is not attaining sufficient SNR, but rather avoiding saturation of the detector. We also desire multi-band photometry to enable clean separation of the QSO and the foreground lens (if there is one), and sufficient depth in the reddest band to detect a foreground lens down to 0.1 L*. We first select the F475W filter (which includes Ly-alpha for this source) and the F160W filter to the broadest possible wavelength coverage. In setting the exposure times, we thus have two criteria. First, we require that individual exposures will not be saturated even if the source is unlensed. This requirement limits us to exposure times shorter than 1 min for the WFC/UVIS F475W filter and <20 s for the WFC3/IR F160W filter. Because of the short exposures, we opt for us of a 512 x 512 sub-array with WFC3/UVIS to increase the efficiency of the program. For F475W, we are using the WFC3-UVIS-LINE-3PT dither pattern with 2x45s exposures at each dither position. This yields a total exposure time of 270s, which provides very high SNR for the QSO but reaches only ~L* for a lens at z = 1 with a passively evolving stellar population. Because of the short exposures and corresponding low background (estimated at 1e'/pixel) we have included FLASH=11 in the options to reach a 12e'/pixel background and mitigate CTE. **Note that we intentionally did not use AUTO-ADJUST in the orbit planning, as this extends the F475W exposures to 55s, which is uncomfortably close to the saturation limit. 15950( 4) - 29-Aug-2019 21:22:31 - [ 2] For the F160W we are using a 4 point dither patter in combination with the SAMP-SEQ=STEP100 and NSAMP=8, for a total exposure time of 796s. The purpose of the F160W imaging is two-fold: (1) to help deblend the QSO and foreground lens, and (2) to identify any galaxy overdensity in the field that may be associated with a protocluster at the redshift of the quasar. The quasar will be saturated beyond NSAMP=4, so the total usable time for the QSO will be 44s (which is sufficient). The total 796s will enable us to reach to <0.1 L* for a z=1 lens at SNR>10. The above imaging, including the associated overheads, fits well within a single orbit. With the remaining fraction of an orbit we therefore add one additional filter, F105W. This remaining time is sufficient for a 1197s F105W observation to match the F160W imaging in reaching < 0.1 L* for a z = 1 lens at SNR= 10. This filter gives additional leverage in deblending a foreground lens, and also for identifying any galaxy overdensity in the field that may be associated with a proto-cluster at the redshift of the quasar. As with F160W we use a 4 point dither pattern with SAMP-SEQ=STEP100, but in this instance set NSAMP=9. Reduced-gryo operations should have no impact on this program. ------------------------------------------------------------------------------------ 15950( 4) - 29-Aug-2019 21:22:31 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 2MASSJ132603 GALAXY, QSO RA=13H26M3.9952S, J2000 V = 16.4 +/- 0.1 99+7023462 DEC=+70D23'46.31" Reference Frame: ICRS Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 0.0 0.0 0 ------------------------------------------------------------------------------------------------------------------------------------ 15950( 4) - 29-Aug-2019 21:22:31 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.135 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.572 Line_Spacing 0.365 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 15950( 4) - 29-Aug-2019 21:22:31 - [ 5] Visit: 01 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 2MASSJ13260 WFC3/UVI ACCUM UVIS2-C51 F475W FLASH=11 2 45 S (270 GS ACQ SCENARIO BASE1B3; 399+7023462 S 2C-SUB S) PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 2MASSJ13260 WFC3/IR MULTIAC IR F105W NSAMP=9, SAMP-SEQ=STEP100 1 DEF PATTERN 2 2 399+7023462 CUM (1196.925 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 2MASSJ13260 WFC3/IR MULTIAC IR F160W NSAMP=8, SAMP-SEQ=STEP100 1 DEF PATTERN 2 3 399+7023462 CUM (796.924 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2MASSJ13260399+7023 1 WFC3/UVI ACCUM UVIS2-C5 F475W 1 none 1 none 1 N/A 462 S 12C-SUB 2MASSJ13260399+7023 1 WFC3/UVI ACCUM UVIS2-C5 F475W 1 none 2 none 1 N/A 462 S 12C-SUB 2MASSJ13260399+7023 1 WFC3/UVI ACCUM UVIS2-C5 F475W 2 none 1 none 1 N/A 462 S 12C-SUB 2MASSJ13260399+7023 1 WFC3/UVI ACCUM UVIS2-C5 F475W 2 none 2 none 1 N/A 462 S 12C-SUB 2MASSJ13260399+7023 1 WFC3/UVI ACCUM UVIS2-C5 F475W 3 none 1 none 1 N/A 462 S 12C-SUB 2MASSJ13260399+7023 1 WFC3/UVI ACCUM UVIS2-C5 F475W 3 none 2 none 1 N/A 462 S 12C-SUB 2MASSJ13260399+7023 2 WFC3/IR MULTIAC IR F105W 1 none none none 1 N/A 462 CUM 2MASSJ13260399+7023 2 WFC3/IR MULTIAC IR F105W 2 none none none 1 N/A 462 CUM 2MASSJ13260399+7023 2 WFC3/IR MULTIAC IR F105W 3 none none none 1 N/A 462 CUM 2MASSJ13260399+7023 2 WFC3/IR MULTIAC IR F105W 4 none none none 1 N/A 462 CUM 2MASSJ13260399+7023 3 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A 462 CUM 2MASSJ13260399+7023 3 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A 462 CUM 15950( 4) - 29-Aug-2019 21:22:31 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2MASSJ13260399+7023 3 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A 462 CUM 2MASSJ13260399+7023 3 WFC3/IR MULTIAC IR F160W 4 none none none 1 N/A 462 CUM 15950( 4) - 29-Aug-2019 21:22:31 - [ 7] Summary Form for Proposal 15950 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, UVIS2-C512C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=11, NSAMP=8, NSAMP=9, SAMP-SEQ=STEP100 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1B3, PATTERN 1 1, PATTERN 2 2, PATTERN 2 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F105W, F160W, F475W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 2MASSJ13260399+7023462 ------------------------------------------------------------------------------------------------------------------------------------