17301( 3) - 13-Apr-2023 15:13:05 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17301 Version: 3 Check-in Time: 13-Apr-2023 15:13:05 STScI Edit Number: 1 Title Ultraviolet imaging of a candidate runaway supermassive black hole ------------------------------------------------------------------------------------ Type Cycle GO 30 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Pieter van Dokkum Yale University Y CoI: Imad Pasha Yale University N CoI: Michael Keim Yale University N CoI: Zili Shen Yale University N CoI: Prof. Roberto G. Abraham University of Toronto N CoI: Prof. Charlie Conroy Harvard University N CoI: Prof. Aaron Romanowsky San Jose State Univ. Research Foundation N CoI: Maria Luisa Buzzo Swinburne University of Technology N CoI: Dr. Grant R. Tremblay Smithsonian Institution Astrophysical N Observatory ------------------------------------------------------------------------------------ Abstract A recent study announced the discovery in HST/ACS data of a remarkably thin, 62 kpc long feature associated with a compact galaxy at z=0.964. It was proposed that we are witnessing shocks and star formation in the wake of a runaway supermassive black hole (SMBH). The existing HST data sample the rest-frame near-UV, and show where stars have formed in the feature. A ground-based u band image shows that the rest-frame far-UV emission is qualitatively different from the rest-frame near-UV: the linear feature is longer, extending all the way to the compact galaxy, and there is flux on the other side of the galaxy, opposite the linear feature that is in the ACS data. The rest-frame far-UV emission likely traces shocked gas rather than (only) hot stars, and the u band detection on the other side may be another wake, behind a simultaneously ejected binary SMBH. The interpretation is hampered by the low resolution of the ground-based u band data. Here we propose to obtain high resolution, deep UV imaging of this remarkable system with UVIS. These observations will show whether there is indeed a counter linear feature, whether it is connected to a compact object that would be the location of the binary SMBH, and whether it shows the characteristic fanning out from the tip that is expected for the wake of a SMBH. The data will also map the rest-frame far-UV emission around the tip of the main feature, which could resolve into a spectacular kpc-scale bow shock. The observations will be done in the difference bandpass F200LP - F350LP. As a bonus, the summed image (F200LP + F350LP) will provide a monochromatic image of the entire system that is 30x deeper than the existing ACS data. ------------------------------------------------------------------------------------ Observations Description ------------------------ The observations are split into 6 visits of 2 orbits each. Within each visit, the first orbit is in F200LP and the second in F350LP. As the science comes from the difference frames F200LP - F350LP, we want to make sure that the F200LP data are taken in the exact same way (with the same ORIENT 17301( 3) - 13-Apr-2023 15:13:05 - [ 2] etc) as the F350LP data. We therefore observe in both filters in each visit. (Rather than, say, having 6 visits of F200LP observations and 6 visits in F350LP). The target is placed at the UVIS2 aperture. The UVIS2 chip has a higher QE in the UV than UVIS1, and as the target is small we do not need to place it near the center of the full array. We contemplated placing the target nearer amplifier C to improve CTE, but given the high background in the long pass filters we figured that UVIS2 is going to be OK. Within each orbit, three exposures are obtained with the WFC3-UVIS-DITHER-LINE-3PT pattern. We are not concerned with dithering over the chip gap, and this pattern improves subpixel sampling. Doing 3 pointings (rather than 2 or a box of 2x2) is a compromise between limiting overheads, having a high enough background to limit CTE losses, and having enough exposures for redundancy and subpixel sampling. In the end we will have 18 exposures in each band and that will certainly be sufficient. The sky background of each exposure is about 85 counts, which is hopefully sufficient. There are no ORIENT or timing constraints. It is also fine if different visits are taken at different ORIENTs. ------------------------------------------------------------------------------------ 17301( 3) - 13-Apr-2023 15:13:05 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 WAKE GALAXY, HIGH REDSHIFT RA=02H41M45.5760S, J2000 V = 25 GALAXY, SHOCK FRONT DEC=-08D20'58.92" Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 17301( 3) - 13-Apr-2023 15:13:05 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 17301( 3) - 13-Apr-2023 15:13:05 - [ 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 WAKE WFC3/UVI ACCUM UVIS2 F200LP 1 700 S GS ACQ SCENARIO BASE1B3; S see below PATTERN 1 1 (2496 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WAKE WFC3/UVI ACCUM UVIS2 F350LP 1 700 S PATTERN 1 2 S see below (2487 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 | ------------------------------------------------------------------------------------------------------------------------------------ WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 1 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 2 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 3 none none none 1 832.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 3 none none none 2 829.0 S S 17301( 3) - 13-Apr-2023 15:13:05 - [ 6] Visit: 02 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 WAKE WFC3/UVI ACCUM UVIS2 F200LP 1 700 S GS ACQ SCENARIO BASE1B3; S see below PATTERN 1 1 (2496 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WAKE WFC3/UVI ACCUM UVIS2 F350LP 1 700 S PATTERN 1 2 S see below (2487 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 | ------------------------------------------------------------------------------------------------------------------------------------ WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 1 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 2 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 3 none none none 1 832.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 3 none none none 2 829.0 S S 17301( 3) - 13-Apr-2023 15:13:05 - [ 7] Visit: 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 WAKE WFC3/UVI ACCUM UVIS2 F200LP 1 700 S GS ACQ SCENARIO BASE1B3; S see below PATTERN 1 1 (2496 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WAKE WFC3/UVI ACCUM UVIS2 F350LP 1 700 S PATTERN 1 2 S see below (2487 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 | ------------------------------------------------------------------------------------------------------------------------------------ WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 1 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 2 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 3 none none none 1 832.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 3 none none none 2 829.0 S S 17301( 3) - 13-Apr-2023 15:13:05 - [ 8] Visit: 04 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 WAKE WFC3/UVI ACCUM UVIS2 F200LP 1 700 S GS ACQ SCENARIO BASE1B3; S see below PATTERN 1 1 (2496 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WAKE WFC3/UVI ACCUM UVIS2 F350LP 1 700 S PATTERN 1 2 S see below (2487 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 | ------------------------------------------------------------------------------------------------------------------------------------ WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 1 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 2 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 3 none none none 1 832.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 3 none none none 2 829.0 S S 17301( 3) - 13-Apr-2023 15:13:05 - [ 9] Visit: 05 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 WAKE WFC3/UVI ACCUM UVIS2 F200LP 1 700 S GS ACQ SCENARIO BASE1B3; S see below PATTERN 1 1 (2496 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WAKE WFC3/UVI ACCUM UVIS2 F350LP 1 700 S PATTERN 1 2 S see below (2487 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 | ------------------------------------------------------------------------------------------------------------------------------------ WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 1 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 2 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 3 none none none 1 832.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 3 none none none 2 829.0 S S 17301( 3) - 13-Apr-2023 15:13:05 - [ 10] Visit: 06 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 WAKE WFC3/UVI ACCUM UVIS2 F200LP 1 700 S GS ACQ SCENARIO BASE1B3; S see below PATTERN 1 1 (2496 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WAKE WFC3/UVI ACCUM UVIS2 F350LP 1 700 S PATTERN 1 2 S see below (2487 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 | ------------------------------------------------------------------------------------------------------------------------------------ WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 1 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 2 none none none 1 832.0 S S WAKE 1 WFC3/UVI ACCUM UVIS2 F200LP 3 none none none 1 832.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 2 829.0 S S WAKE 2 WFC3/UVI ACCUM UVIS2 F350LP 3 none none none 2 829.0 S S 17301( 3) - 13-Apr-2023 15:13:05 - [ 11] Summary Form for Proposal 17301 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1B3, PATTERN 1 1, PATTERN 1 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F200LP, F350LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names WAKE ------------------------------------------------------------------------------------------------------------------------------------