16505( 2) - 15-Mar-2021 15:33:46 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16505 Version: 2 Check-in Time: 15-Mar-2021 15:33:46 STScI Edit Number: 0 Title From a soft gamma-repeater to a fast radio burst ------------------------------------------------------------------------------------ Type Cycle GO 28 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Andrew James Levan Radboud Universiteit Nijmegen Y CoI: Dr. Andrew S. Fruchter Space Telescope Science Institute N CoI: Dr. C. Kouveliotou George Washington University N CoI: Dr. Ashley Chrimes Radboud Universiteit Nijmegen N ------------------------------------------------------------------------------------ Abstract The origin of the Fast Radio Bursts (FRBs) has become one of the central questions in contemporary astrophysics. Several lines of evidence have pointed to their association with some form of magnetar flare, occurring in external galaxies. However, this is by no means a unique explanation, with other viable models also suggested. A significant step forward in this field occurred with the apparent detection of a millisecond radio burst (essentially an FRB) from the Galactic magnetar SGR 1935+2154. This magnetar is one of the most active known and continues to undergo an unprecedented period of activity with an intensive ongoing campaign. Fortuitously, HST has previously observed the magnetar, locating an IR counterpart. Here we request a single orbit observation that will detect it in its current active state. This observation will enable us to test how the optical/IR emission appears after the FRB providing vital insight to other searches for optical/IR counterparts of FRBs in external galaxies. Furthermore, as the source is currently active and sufficiently bright for detection, a proper motion measurement with a 6-year baseline will be possible. The proper motion will enable the magnetar to be tracked back to its birth-site, testing its assocaition with a supernova remnant, as well as providing a route for comparing its velocity with that of the general pulsar population. ------------------------------------------------------------------------------------ Observations Description ------------------------ The aim of this proposal is to obtain observations of SGR 1935+2154 to obtain a detection of its counterpart and a measurement (or limits) on its proper motion. Because the source is variable and active now the observations should be taken quickly. However, there is also a significant advantage to matching the orient of the observations with those taken previously. We will repeat the observational set-up previously used which is a simple 4-point dither pattern using the STEP reads for dynamic range. ------------------------------------------------------------------------------------ 16505( 2) - 15-Mar-2021 15:33:46 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SGR1935+2154 EXT-STAR, NEUTRON STAR RA=19H34M55.6800S, J2000 V = 27 +/- 1 DEC=+21D53'48.20" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 16505( 2) - 15-Mar-2021 15:33:46 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 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 ------------------------------------------------------------------------------------------------------------------------------------ 16505( 2) - 15-Mar-2021 15:33:46 - [ 4] Visit: 01 Visit Requirements: ORIENT 205.218D TO 205.219 D; BEFORE 15-JUN-2021:00:00:00 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 SGR1935+215 WFC3/IR MULTIAC IR F140W NSAMP=12, SAMP-SEQ=STEP100 1 DEF PATTERN 1 1 4 CUM (2396.929 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 | ------------------------------------------------------------------------------------------------------------------------------------ SGR1935+2154 1 WFC3/IR MULTIAC IR F140W 1 none none none 1 N/A CUM SGR1935+2154 1 WFC3/IR MULTIAC IR F140W 2 none none none 1 N/A CUM SGR1935+2154 1 WFC3/IR MULTIAC IR F140W 3 none none none 1 N/A CUM SGR1935+2154 1 WFC3/IR MULTIAC IR F140W 4 none none none 1 N/A CUM 16505( 2) - 15-Mar-2021 15:33:46 - [ 5] Summary Form for Proposal 16505 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=12, SAMP-SEQ=STEP100 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 15-JUN-2021:00:00:00, ORIENT 205.218D TO 205.219 D, PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F140W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SGR1935+2154 ------------------------------------------------------------------------------------------------------------------------------------