16063( 3) - 06-Apr-2020 16:45:27 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16063 Version: 3 Check-in Time: 06-Apr-2020 16:45:27 STScI Edit Number: 0 Title The First Glimpse of A Candidate Recoiling Black Hole ------------------------------------------------------------------------------------ Type Cycle GO 27 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Michael J Koss Eureka Scientific Inc. Y CoI: Mr. Kyuseok Oh Yonsei University N CoI: Dr. Benny Trakhtenbrot Tel Aviv University N CoI: Prof. Claudio Ricci Diego Portales University N CoI: Dr. Richard Mushotzky University of Maryland N CoI: Mr. Jakob Sebastiaan den Brok ETH Zurich N CoI: Dr. Meredith Powell Stanford University N ------------------------------------------------------------------------------------ Abstract The coalescence of binary supermassive black holes (SMBH) in galaxy mergers is thought to constitute the strongest source of gravitational waves. Theory suggests these waves carry momentum causing the merged black hole to experience a velocity recoil or kick that displaces or indeed ejects it from the center of its host galaxy. We request the first XMM-Newton and HST imaging of RXJ1756.4+5235, a source with an o ffset broad line point source that is offset from the nucleus of a nearby galaxy to resolve whether the source is a potential recoiling black hole or a close dual AGN. ------------------------------------------------------------------------------------ Observations Description ------------------------ The point of this observation is to look for extended emission around a point source to test for the presence of a possible recoiling black hole using the i-band and the H-band with WFC3. The object looks like a point source separated by 6.4'' with QSO like emission from a nearby galaxy with extended emission. The WFC3 UVIS detector with F814W will provide the sharpest images with a smaller plate scale to best sample the PSF (0.04''). The F160W observation is critical since the NIR traces the bulk of the stellar mass because ofits sensitivity to the cooler stars in older stellar populations and the NIR is also much less aected by dust extinction. We have designed our images to avoid saturation, but also to limit overheads, so that we have maximal sensitivity to faint features from a host galaxy in the potential recoiling black hole. The i-band psf mag from PS1, is 17.06, which leads to saturation in images of 256s assuming a QSO IRTF template. We chose a 2048x2048 subarray to minizimize buffer dump time. In order to have an unsaturated image we take a short image for 23 seconds followed by a 4 point dither pattern with 591s at each pointing. We use a 4-point dither pattern to improve PSF reconstruction/cosmic rays. On the other hand, in the F160W images, based on the PSF z-band mag of 16.99 and assuming a QSO template there is a saturation in 28 seconds. We note the 16063( 3) - 06-Apr-2020 16:45:27 - [ 2] UKIDSS J-mag is somewhat shorter integrations at 15.43mag in J (2'' diameter aperture) which suggests saturation in 24 seconds, but we expect it contains some amount of extended flux from the nearby host galaxy. We use the 512x512 subarray to reduce readout and buffer dump. This provides a field-of-view (FOV) of 60''x60''. We will use the 4-step BOX dither pattern with 16 reads for cosmic-ray and hot-pixel rejection, and to better sample the PSF. ------------------------------------------------------------------------------------ 16063( 3) - 06-Apr-2020 16:45:27 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 RXJ1756.4+52 GALAXY, QUASAR RA=17H56M24.8000S, J2000 V = 18.15 i=17.05, 15.43 J 35 DEC=+52D35'20.40" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 16063( 3) - 06-Apr-2020 16:45:27 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 1.716 Line_Spacing 1.095 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16063( 3) - 06-Apr-2020 16:45:27 - [ 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 RXJ1756.4+5 WFC3/UVI ACCUM UVIS2-C51 F814W FLASH=14 1 23 S (23 235 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 RXJ1756.4+5 WFC3/UVI ACCUM UVIS1-2K2 F814W 1 591 S PATTERN 4 2 235 S A-SUB (2364 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 RXJ1756.4+5 WFC3/IR MULTIAC IRSUB512 F160W SAMP-SEQ=STEP25, NSAMP=15 1 DEF PATTERN 1 3-5 235 CUM (972.184 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 RXJ1756.4+5 WFC3/IR MULTIAC IRSUB512 F160W SAMP-SEQ=SPARS25, NSAMP=10 1 DEF 235 CUM (828.577 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 RXJ1756.4+5 WFC3/IR MULTIAC IRSUB512 F160W SAMP-SEQ=SPARS25, NSAMP=10 1 DEF 235 CUM (828.577 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 | ------------------------------------------------------------------------------------------------------------------------------------ RXJ1756.4+5235 1 WFC3/UVI ACCUM UVIS2-C5 F814W none none none none 1 N/A S 12C-SUB RXJ1756.4+5235 2 WFC3/UVI ACCUM UVIS1-2K F814W 1 none none none 1 N/A S 2A-SUB RXJ1756.4+5235 2 WFC3/UVI ACCUM UVIS1-2K F814W 2 none none none 1 N/A S 2A-SUB RXJ1756.4+5235 2 WFC3/UVI ACCUM UVIS1-2K F814W 3 none none none 1 N/A S 2A-SUB RXJ1756.4+5235 2 WFC3/UVI ACCUM UVIS1-2K F814W 4 none none none 1 N/A S 2A-SUB RXJ1756.4+5235 3 WFC3/IR MULTIAC IRSUB512 F160W 1 none none none 2 N/A CUM RXJ1756.4+5235 3 WFC3/IR MULTIAC IRSUB512 F160W 2 none none none 2 N/A CUM RXJ1756.4+5235 3 WFC3/IR MULTIAC IRSUB512 F160W 3 none none none 2 N/A CUM RXJ1756.4+5235 3 WFC3/IR MULTIAC IRSUB512 F160W 4 none none none 2 N/A CUM 16063( 3) - 06-Apr-2020 16:45:27 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ RXJ1756.4+5235 4 WFC3/IR MULTIAC IRSUB512 F160W 1 none none none 2 N/A CUM RXJ1756.4+5235 4 WFC3/IR MULTIAC IRSUB512 F160W 2 none none none 2 N/A CUM RXJ1756.4+5235 4 WFC3/IR MULTIAC IRSUB512 F160W 3 none none none 2 N/A CUM RXJ1756.4+5235 4 WFC3/IR MULTIAC IRSUB512 F160W 4 none none none 2 N/A CUM RXJ1756.4+5235 5 WFC3/IR MULTIAC IRSUB512 F160W 1 none none none 2 N/A CUM RXJ1756.4+5235 5 WFC3/IR MULTIAC IRSUB512 F160W 2 none none none 2 N/A CUM RXJ1756.4+5235 5 WFC3/IR MULTIAC IRSUB512 F160W 3 none none none 2 N/A CUM RXJ1756.4+5235 5 WFC3/IR MULTIAC IRSUB512 F160W 4 none none none 2 N/A CUM 16063( 3) - 06-Apr-2020 16:45:27 - [ 7] Summary Form for Proposal 16063 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IRSUB512, UVIS1-2K2A-SUB, UVIS2-C512C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=14, NSAMP=10, NSAMP=15, SAMP-SEQ=SPARS25, SAMP-SEQ=STEP25 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 3-5, PATTERN 4 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F160W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names RXJ1756.4+5235 ------------------------------------------------------------------------------------------------------------------------------------