15441( 4) - 14-Feb-2018 16:04:13 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15441 Version: 4 Check-in Time: 14-Feb-2018 16:04:13 STScI Edit Number: 0 Title Follow-up Observation of a Hyperluminous Intermediate-mass Black Hole Candidate ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Dacheng Lin University of New Hampshire Y CoI: Dr. Natalie A. Webb Observatoire Midi-Pyrenees N CoI: Dr. Olivier Godet Observatoire Midi-Pyrenees N CoI: Dr. Didier Barret Observatoire Midi-Pyrenees N CoI: Dr. Jeroen Homan Eureka Scientific Inc. N CoI: Prof. Jimmy A. Irwin University of Alabama N CoI: Prof. Aaron Romanowsky San Jose State University N CoI: Dr. Ronald Remillard Massachusetts Institute of Technology N ------------------------------------------------------------------------------------ Abstract Intermediate-mass black holes (IMBH, ~10^2-10^5 msun) have been long sought after because they are associated with several important astrophysical processes. The best IMBH candidates are hyperluminous off-nuclear X-ray sources (HLXs) with LX>10^41 erg/s, but very few are known. We have identified a new HLX candidate (LX~10^43 erg/s), at an offset of 11.6" (12 kpc) from the center of its host galaxy (D L=247 Mpc). We request a deep (60 ks) XMM-Newton observation of the source in AO17 to measure its flux and spectral evolution while it is in the decay phase of a prolonged outburst, in order to demonstrate its IMBH nature and confirm our tidal disruption event explanation for the outburst. An HST orbit is also requested to confirm that our source is in a star cluster. ------------------------------------------------------------------------------------ Observations Description ------------------------ The program will have one orbit observation of a hyperluminous X-ray source at a distance of 247 Mpc using ACS/WFC F775W. It uses a dither-box patterm, with 544 second per exposure (2176 s in total). ------------------------------------------------------------------------------------ 15441( 4) - 14-Feb-2018 16:04:13 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 3XMMJ215022. STELLAR CLUSTER, RA=21H50M21.6000S +/- 0.1", J2000 V = 24.60 +/- 0.06 4-055108 ACCRETION DISK, DEC=-05D51'3.89" +/- 0.1" GLOBULAR CLUSTER Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 15441( 4) - 14-Feb-2018 16:04:13 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.262 Line_Spacing 0.192 Coordinate_Frame POS-TARG Pattern_Orient 18.39 Angle_Between_Sides 68.14 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 15441( 4) - 14-Feb-2018 16:04:13 - [ 4] Visit: 01 Visit Requirements: ORIENT 225D TO 273 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 3XMMJ215022 ACS/WFC ACCUM WFC1-CTE F775W GAIN=2.0 1 544 S POS TARG -25, -15; .4-055108 (2176 S) PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 3XMMJ215022.4-05510 1 ACS/WFC ACCUM WFC1-CTE F775W 1 none none none 1 N/A 8 3XMMJ215022.4-05510 1 ACS/WFC ACCUM WFC1-CTE F775W 2 none none none 1 N/A 8 3XMMJ215022.4-05510 1 ACS/WFC ACCUM WFC1-CTE F775W 3 none none none 1 N/A 8 3XMMJ215022.4-05510 1 ACS/WFC ACCUM WFC1-CTE F775W 4 none none none 1 N/A 8 15441( 4) - 14-Feb-2018 16:04:13 - [ 5] Summary Form for Proposal 15441 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC1-CTE ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters GAIN=2.0 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 225D TO 273 D, PATTERN 1 1, POS TARG -25, -15 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F775W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 3XMMJ215022.4-055108 ------------------------------------------------------------------------------------------------------------------------------------