[vsnet-grb-info 19939] GRB 171011B: Insight-HXMT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22026
SUBJECT: GRB 171011B: Insight-HXMT detection
DATE:    17/10/19 09:45:28 GMT
FROM:    Juan Zhang at IHEP/CAS/POLAR  <zhangjuan at ihep.ac.cn>

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


During the commissioning phase, at 2017-10-11T01:05:36 (T0),
Insight-HXMT/HE detected GRB 171011B (trigger ID: HEB171011045)
in a routine search of the data, which is also detected by CALET
(Marrocchesi et al., GCN 22022) and INTEGRAL, etc. 
This burst has been localized by IPN triangulation
(Hurley et al., GCN Circ. 21998).


The Insight-HXMT light curve consists of multi-pulses
with a duration (T90) of 1.6 s measured from T0+1.3 s to T0+2.9 s.
The 20-ms peak rate, measured from T0+1.98 s, is 23852.4 cnts/sec.
The total counts from this burst is 19179.3 counts.


URL_LC: http://www.hxmt.org/images/GRB/HEB171011B_LC.pdf


The time-averaged spectrum from T0-1 s to T0+7 s is
adequately fit by a Band spectrum with alpha = 3.94 +/- 0.86, 
beta = -2.65 +/- 0.16 and E_peak = 339.29 +/- 19.71.
The energy fluence is (5.45 +/- 0.24)E-05 erg/cm^2 in 200 - 5000 keV 
in this time interval.


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 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 .