TY - JOUR
T1 - Constraining the X-Ray-Infrared Spectral Index of Second-timescale Flares from SGR 1935+2154 with Palomar Gattini-IR
AU - De, Kishalay
AU - Ashley, Michael C. B.
AU - Andreoni, Igor
AU - Kasliwal, Mansi M.
AU - Soria, Roberto
AU - Srinivasaragavan, Gokul P.
AU - Cai, Ce
AU - Delacroix, Alexander
AU - Greffe, Tim
AU - Hale, David
AU - Hankins, Matthew J.
AU - Li, Chengkui
AU - McKenna, Daniel
AU - Moore, Anna M.
AU - Ofek, Eran O.
AU - Smith, Roger M.
AU - Soon, Jamie
AU - Travouillon, Tony
AU - Zhang, Shuangnan
N1 - We thank the Insight/HXMT team for their kind cooperation in coordinating observations and quickly providing fluence estimates. We thank K. Smith for cooperation regarding the CHIME observability windows. We thank C. Bochenek, W. Lu, V. Ravi, and S. R. Kulkarni for valuable discussions on this work. Palomar Gattini-IR (PGIR) is generously funded by Caltech, Australian National University, the Mt Cuba Foundation, the Heising Simons Foundation, the Bi-national Science Foundation. PGIR is a collaborative project among Caltech, Australian National University, University of New South Wales, Columbia University and the Weizmann Institute of Science. This work was supported by the GROWTH (Global Relay of Observatories Watching Transients Happen) project funded by the National Science Foundation under PIRE grant No 1545949. GROWTH is a collaborative project among the California Institute of Technology (USA), University of Maryland College Park (USA), University of Wisconsin Milwaukee (USA), Texas Tech University (USA), San Diego State University (USA), University of Washington (USA), Los Alamos National Laboratory (USA), Tokyo Institute of Technology (Japan), National Central University (Taiwan), Indian Institute of Astrophysics (India), Indian Institute of Technology Bombay (India), Weizmann Institute of Science (Israel), The Oskar Klein Centre at Stockholm University (Sweden), Humboldt University (Germany), Liverpool John Moores University (UK), and University of Sydney (Australia).
PY - 2020/9
Y1 - 2020/9
N2 - The Galactic magnetar SGR 1935+2154 has been reported to produce the first example of a bright millisecond-duration radio burst (FRB 200428) similar to the cosmological population of fast radio bursts (FRBs). The detection of a coincident bright X-ray burst represents the first observed multiwavelength counterpart of an FRB. However, the search for similar emission at optical wavelengths has been hampered by the high inferred extinction on the line of sight. Here, we present results from the first search for second-timescale emission from the source at near-infrared (NIR) wavelengths using the Palomar Gattini-IR observing system in theJband, enabled by a novel detector readout mode that allows short exposure times of 0.84 s with 99.9% observing efficiency. With a total observing time of 12 hr (47,728 images) during its 2020 outburst, we place median 3 sigma limits on the second-timescale NIR fluence of less than or similar to 18 Jy ms (13.1 AB mag). The corresponding extinction-corrected limit is less than or similar to 125 Jy ms for an estimated extinction ofA(J) = 2.0 mag. Our observations were sensitive enough to easily detect an NIR counterpart of FRB 200428 if the NIR emission falls on the same power law as observed across its radio to X-ray spectrum. We report nondetection limits from epochs of four simultaneous X-ray bursts detected by the Insight-HXMT and NuSTAR telescopes during our observations. These limits provide the most stringent constraints to date on fluence of flares at similar to 10(14)Hz, and constrain the fluence ratio of the NIR emission to coincident X-ray bursts toR(NIR) less than or similar to 0.025 (fluence index greater than or similar to 0.35).
AB - The Galactic magnetar SGR 1935+2154 has been reported to produce the first example of a bright millisecond-duration radio burst (FRB 200428) similar to the cosmological population of fast radio bursts (FRBs). The detection of a coincident bright X-ray burst represents the first observed multiwavelength counterpart of an FRB. However, the search for similar emission at optical wavelengths has been hampered by the high inferred extinction on the line of sight. Here, we present results from the first search for second-timescale emission from the source at near-infrared (NIR) wavelengths using the Palomar Gattini-IR observing system in theJband, enabled by a novel detector readout mode that allows short exposure times of 0.84 s with 99.9% observing efficiency. With a total observing time of 12 hr (47,728 images) during its 2020 outburst, we place median 3 sigma limits on the second-timescale NIR fluence of less than or similar to 18 Jy ms (13.1 AB mag). The corresponding extinction-corrected limit is less than or similar to 125 Jy ms for an estimated extinction ofA(J) = 2.0 mag. Our observations were sensitive enough to easily detect an NIR counterpart of FRB 200428 if the NIR emission falls on the same power law as observed across its radio to X-ray spectrum. We report nondetection limits from epochs of four simultaneous X-ray bursts detected by the Insight-HXMT and NuSTAR telescopes during our observations. These limits provide the most stringent constraints to date on fluence of flares at similar to 10(14)Hz, and constrain the fluence ratio of the NIR emission to coincident X-ray bursts toR(NIR) less than or similar to 0.025 (fluence index greater than or similar to 0.35).
UR - http://www.scopus.com/inward/record.url?scp=85092231030&partnerID=8YFLogxK
U2 - https://doi.org/10.3847/2041-8213/abb3c5
DO - https://doi.org/10.3847/2041-8213/abb3c5
M3 - مقالة
SN - 2041-8205
VL - 901
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - 7
ER -