LIGO/Virgo S190930s: Upper limits from Insight-HXMT/HE observations
Abstract
Insight-HXMT was taking data normally around the reported LIGO/Virgo S190930s event (GCN #25871), trigger time 2019-09-30T13:35:41 UTC. At T0, about 57% of the LIGO localization region was covered by Insight-HXMT without occultation by the Earth. Within T0 +/- 100 s, no significant excess events (SNR > 3 sigma) are found in a search of the Insight-HXMT/HE raw light curves. Assuming the GW counterpart GRB with three typical GRB Band spectral models, two typical duration timescales (1 s, 10 s) from the center of the LIGO-Virgo location probability map (RA=313 deg, DEC=19 deg), the 5-sigma upper-limits fluence (0.2 - 5 MeV, incident energy) are reported below: Band model 1 (alpha=-1.9, beta=-3.7, Ep=70 keV): 1 s: 2.1e-07 erg cm^-2 10 s: 5.0e-07 erg cm^-2 Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV): 1 s: 3.0e-07 erg cm^-2 10 s: 7.6e-07 erg cm^-2 Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV): 1 s: 4.6e-07 erg cm^-2 10 s: 1.3e-06 erg cm^-2 All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the spacecraft. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information could be found at: http://www.hxmt.org.
- Publication:
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GRB Coordinates Network
- Pub Date:
- October 2019
- Bibcode:
- 2019GCN.25933....1L