LIGO/Virgo S200302c: Upper limits from Insight-HXMT/HE observations
Abstract
Insight-HXMT was taking data normally around the reported LIGO/Virgo S200302c event (GCN #27278). At the GW trigger time 2020-03-02T01:58:21.38 UTC (denoted as T0), about 55.0% of the GW localization region was covered by the 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=40.1 deg, DEC=70.0 deg) without occultation by the Earth, 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: 3.2e-07 erg cm^-2 10 s: 1.4e-06 erg cm^-2 Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV): 1 s: 4.5e-07 erg cm^-2 10 s: 1.6e-06 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: 1.7e-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.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- March 2020
- Bibcode:
- 2020GCN.27310....1L