Q. Luo, C. Cai, Q. B. Yi, S. Xiao, C. K. Li,
X. B. Li, G. Li, J. Y. Liao, S. L. Xiong,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang,
Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin,
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song,
M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:
Following up on the updated localization (GCN #24448), we have
re-analyzed Insight-HXMT/HE data of S190510g (GCN #24451).
The previous estimated location we used (GCN #24451) is
RA = 190.0, Dec = 0.0 (J2000, degrees).
And the updated estimated location we used is
RA = 90.0, Dec = -34.0 (J2000, degrees).
Insight-HXMT was taking data normally around the GW trigger time
(T0=2019-05-10 02:59:39 UTC). For the preferred sky map (GCN #24448),
at T0, all 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 peak
position of the LIGO-Virgo location probability map, 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: 5.5e-08 erg cm^-2
10 s: 1.5e-07 erg cm^-2
Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV):
1 s: 9.2e-08 erg cm^-2
10 s: 2.6e-07 erg cm^-2
Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV):
1 s: 2.4e-07 erg cm^-2
10 s: 8.3e-07 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.