[vsnet-grb-info 19723] GRB 170817B: Insight-HXMT observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21593
SUBJECT: GRB 170817B: Insight-HXMT observation
DATE:    17/08/19 13:32:35 GMT
FROM:    Shaolin Xiong at IHEP  <xiongsl at ihep.ac.cn>

Z. W. Li, J. Y. Liao, C. K. Li, X. B. Li, S. L. Xiong, C. Z. Liu,
X. F. Li, Z. Chang, X. F. Lu, J. L. Zhao, A. M. Zhang, Y. F. Zhang,
C. L. Zou (IHEP), Y. J. Jin, X. Ma, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:

During the commissioning phase, at 2017-08-17T21:47:34.00 (T0),
Insight-HXMT detected GRB 170817B (trigger ID: HEB170817908)
in a routine search of the data, which was also observed by
Fermi/GBM (Roberts et al. 2017, GCN 21540).

The Insight-HXMT light curve consists of multiple pulses
with a duration (T90) of 2.64 s measured from T0+0.40 s.
The 50-ms peak rate, measured from T0+0.40 s, is 6135.4 cnts/sec.
The total counts from this burst is 5353.1 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB170817908_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record 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 telescope.

The time-averaged spectrum from T0 to T0+3.60 s is
adequately fit by a Power Law model with spectral index = -1.60 +/- 0.05.
The energy fluence is (1.09 +/- 0.05)E-05 erg/cm^2 in 200 - 5000 keV in
this time interval.

The analysis results presented above are preliminary;
final results will be published elsewhere.

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 about it could be found at:
http://www.hxmt.org/index.php/enhome .