14922( 3) - 27-Mar-2017 20:31:43 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14922 Version: 3 Check-in Time: 27-Mar-2017 20:31:43 STScI Edit Number: 0 Title Probing the Nature of Dark Matter with Individual Stars Highly Magnified by a Galaxy Cluster ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Patrick Kelly University of California - Berkeley Y CoI: Prof. Tommaso L. Treu University of California - Los Angeles N CoI: Dr. Steven A. Rodney University of South Carolina Research N Foundation CoI: Dr. Jose M. Diego Instituto de Fisica de Cantabria N CoI: Prof. Masamune Oguri Institute for Physics and Mathematics of N the Universe CoI: Dr. Adi Zitrin Ben Gurion University of the Negev N CoI: Dr. Saurabh W. Jha Rutgers the State University of New Jersey N CoI: Mr. Jonatan Selsing University of Copenhagen, Niels Bohr N Institute CoI: Dr. Johan Pierre Richard Centre de Recherche Astrophysique de Lyon N CoI: Dr. Mathilde Jauzac Durham Univ. N CoI: Dr. Brenda Louise Frye University of Arizona N CoI: Prof. Alex V. Filippenko University of California - Berkeley N CoI: Dr. Nathan Smith University of Arizona N CoI: Dr. Adam Riess The Johns Hopkins University N CoI: Dr. Benjamin Weiner University of Arizona N CoI: Dr. Laurent Pueyo Space Telescope Science Institute N CoI: Dr. Colin A. Norman The Johns Hopkins University N CoI: Dr. Stephen Bradley Cenko NASA Goddard Space Flight Center N CoI: Prof. Pablo G. Perez-Gonzalez Universidad Complutense de Madrid N CoI: Dr. Alberto Molino Molino Instituto de Astronomia, Geofisica e N Ciencias Atmosfericas CoI: Dr. Nick Kaiser University of Hawaii N CoI: Mr. Takahiro Morishita University of California - Los Angeles N CoI: Prof. Thomas J. Broadhurst University of the Basque Country N CoI: Dr. Selma E. de Mink Universiteit van Amsterdam N CoI: Mr. Xin Wang University of California - Los Angeles N ------------------------------------------------------------------------------------ Abstract A star highly magnified by a galaxy cluster should provide a powerful new tool for probing the composition of dark matter. We discovered the first-known such star (named ''Icarus'') close to the critical curve of the MACS J1149 galaxy cluster in April 2016. The star's spectral energy distribution (SED) shows no change over the last several years, including during its rise to peak brightness in May 2016. The SED is consistent with that of a mid-to-late B-type star at the redshift z=1.49 of the background lensed galaxy, and our models suggest that the star became temporarily magnified by a factor of at least ~2000 at peak. While continuing to monitor the field, we discovered a new, entirely unexpected source (dubbed ''Chucky'') with very high significance ~0.26 arcseconds away from Icarus on October 30, 2016. If Chucky is a counterimage of Icarus, a population of massive objects 14922( 3) - 27-Mar-2017 20:31:43 - [ 2] (>20 solar masses) may be needed to hide it during the ~12 years while the field has been observed. When a follow-up program was able to observe the field to measure its SED, Chucky had faded. However, in a subsequent visit, we detected an additional potential ~4-sigma source (''Perdix'') offset from both Icarus and Chucky. If we continue to detect transients at large offsets, dark matter corresponding to an ultra-light scalar field (Hui et al. 2016) may be required to account for the rate of such events. An ultra-light scalar field would be granular instead of smoothly distributed, leading to microlensing events with large angular separations. The observations of the field, at an optimal cadence for finding microlensing events, will be able to identify distinct stars from their Balmer jumps. ------------------------------------------------------------------------------------ Observations Description ------------------------ Two transients that we understand to be indiidual magnified stars have appeared close (<0.1") to the critical curve of the MACS J1149 galaxy cluster in HST observations that we acquired during Cycle 23 and Cycle 24. As part of this program, we will continue to monitor the field for similar events, which should help us to understand the lens system and place constraints on dark matter in the form of compact objects. This program will consist of five separate one-orbit visits each split between integrations in the WFC3-UVIS F606W and WFC3-IR F125W wideband filters. These observer-frame optical and near-IR filters span the Balmer jump of stars at the redshift (z=1.49) of the lensed background galaxy. The observations will therefore make it possible to place constraints on the photospheric temperatures of lensed stars and distinguish between the images of distinct stars. ------------------------------------------------------------------------------------ 14922( 3) - 27-Mar-2017 20:31:43 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 POSSIBLESTAR EXT-STAR, B6-B9.5 III-I RA=11H49M35.6720S, J2000 V = 27 +/- 1 COUNTERIMAGE DEC=+22D23'48.15" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 14922( 3) - 27-Mar-2017 20:31:43 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 14922( 3) - 27-Mar-2017 20:31:43 - [ 5] Visit: 01 (M1149 F110W/F606W) Visit Requirements: SCHED 100%; ORIENT 123D TO 175 D; BETWEEN 01-APR-2017:00:00:00 AND 21-APR-2017:00:00:00 On Hold Comments: Additional Comments: 3 short WFC3-IR F110W and 3 short WFC3-UVIS F606W exposures of source in the MACS1149 field. 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 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0, 0 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.451, 0.403 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 3 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.902, 0.806 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 4 POSSIBLESTA WFC3/UVI ACCUM UVIS F606W 1 370 S PATTERN 1 4 RCOUNTERIMA S see below GE (1068 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 | ------------------------------------------------------------------------------------------------------------------------------------ POSSIBLESTARCOUNTER 1 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 2 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 3 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 1 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 2 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 3 none none none 1 356.0 S IMAGE S 14922( 3) - 27-Mar-2017 20:31:43 - [ 6] Visit: 02 (M1149 F110W/F606W) Visit Requirements: SCHED 100%; ORIENT 123D TO 153 D; AFTER 01 BY 18 D TO 25 D; BETWEEN 22-APR-2017:00:00:00 AND 13-MAY-2017:00:00:00 On Hold Comments: Additional Comments: 3 short WFC3-IR F110W and 3 short WFC3-UVIS F606W exposures of source in the MACS1149 field. 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 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0, 0 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.451, 0.403 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 3 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.902, 0.806 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 4 POSSIBLESTA WFC3/UVI ACCUM UVIS F606W 1 370 S PATTERN 1 4 RCOUNTERIMA S see below GE (1068 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 | ------------------------------------------------------------------------------------------------------------------------------------ POSSIBLESTARCOUNTER 1 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 2 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 3 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 1 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 2 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 3 none none none 1 356.0 S IMAGE S 14922( 3) - 27-Mar-2017 20:31:43 - [ 7] Visit: 03 (M1149 F110W/F606W) Visit Requirements: SCHED 100%; ORIENT 123D TO 148 D; AFTER 02 BY 18 D TO 25 D; BETWEEN 14-MAY-2017:00:00:00 AND 04-JUN-2017:00:00:00 On Hold Comments: Additional Comments: 3 short WFC3-IR F110W and 3 short WFC3-UVIS F606W exposures of source in the MACS1149 field. 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 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0, 0 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.451, 0.403 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 3 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.902, 0.806 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 4 POSSIBLESTA WFC3/UVI ACCUM UVIS F606W 1 370 S PATTERN 1 4 RCOUNTERIMA S see below GE (1068 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 | ------------------------------------------------------------------------------------------------------------------------------------ POSSIBLESTARCOUNTER 1 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 2 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 3 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 1 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 2 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 3 none none none 1 356.0 S IMAGE S 14922( 3) - 27-Mar-2017 20:31:43 - [ 8] Visit: 04 (M1149 F110W/F606W) Visit Requirements: SCHED 100%; ORIENT 123D TO 148 D; ORIENT 90D TO 98 D; AFTER 03 BY 18 D TO 25 D; BETWEEN 05-JUN-2017:00:00:00 AND 27-JUN-2017:00:00:00 On Hold Comments: Additional Comments: 3 short WFC3-IR F110W and 3 short WFC3-UVIS F606W exposures of source in the MACS1149 field. preferred orients > 123 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 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0, 0 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.451, 0.403 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 3 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.902, 0.806 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 4 POSSIBLESTA WFC3/UVI ACCUM UVIS F606W 1 370 S PATTERN 1 4 RCOUNTERIMA S see below GE (1068 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 | ------------------------------------------------------------------------------------------------------------------------------------ POSSIBLESTARCOUNTER 1 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 2 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 3 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 1 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 2 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 3 none none none 1 356.0 S IMAGE S 14922( 3) - 27-Mar-2017 20:31:43 - [ 9] Visit: 05 (M1149 F110W/F606W) Visit Requirements: SCHED 100%; ORIENT 90D TO 104 D; AFTER 04 BY 18 D TO 45 D; BETWEEN 08-JUL-2017:00:00:00 AND 23-JUL-2017:00:00:00 On Hold Comments: Additional Comments: 3 short WFC3-IR F110W and 3 short WFC3-UVIS F606W exposures of source in the MACS1149 field. preferred orients <= 104 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 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0, 0 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.451, 0.403 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 3 POSSIBLESTA WFC3/IR MULTIAC IR F110W NSAMP=8, SAMP-SEQ=SPARS50 1 DEF POS TARG 0.902, 0.806 RCOUNTERIMA CUM (352.935 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 4 POSSIBLESTA WFC3/UVI ACCUM UVIS F606W 1 370 S PATTERN 1 4 RCOUNTERIMA S see below GE (1068 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 | ------------------------------------------------------------------------------------------------------------------------------------ POSSIBLESTARCOUNTER 1 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 2 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 3 WFC3/IR MULTIAC IR F110W none none none none 1 N/A IMAGE CUM POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 1 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 2 none none none 1 356.0 S IMAGE S POSSIBLESTARCOUNTER 4 WFC3/UVI ACCUM UVIS F606W 3 none none none 1 356.0 S IMAGE S 14922( 3) - 27-Mar-2017 20:31:43 - [ 10] Summary Form for Proposal 14922 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, UVIS ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=8, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 18 D TO 25 D, AFTER 02 BY 18 D TO 25 D, AFTER 03 BY 18 D TO 25 D, AFTER 04 BY 18 D TO 45 D, BETWEEN 01-APR-2017:00:00:00 AND 21-APR-2017:00:00:00, BETWEEN 05-JUN-2017:00:00:00 AND 27-JUN-2017:00:00:00, BETWEEN 08-JUL-2017:00:00:00 AND 23-JUL-2017:00:00:00, BETWEEN 14-MAY-2017:00:00:00 AND 04-JUN-2017:00:00:00, BETWEEN 22-APR-2017:00:00:00 AND 13-MAY-2017:00:00:00, ORIENT 123D TO 148 D, ORIENT 123D TO 153 D, ORIENT 123D TO 175 D, ORIENT 90D TO 104 D, ORIENT 90D TO 98 D, PATTERN 1 4, POS TARG 0, 0, POS TARG 0.451, 0.403, POS TARG 0.902, 0.806, SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W, F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names POSSIBLESTARCOUNTERIMAGE ------------------------------------------------------------------------------------------------------------------------------------