[vsnet-grb-info 19753] GRB 170826B: Insight-HXMT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21739
SUBJECT: GRB 170826B: Insight-HXMT detection
DATE:    17/08/29 03:49:05 GMT
FROM:    Zhengwei Li at IHEP  <lizw 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, 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 2017-08-26T19:38:58.00 (T0),
Insight-HXMT detected GRB 170826B (trigger ID: HEB170826818)
in a routine search of the data, which was also observed by
Fermi/GBM (Poolakkil et al, GCN Circ.21717).


The Insight-HXMT light curve consists of multiple pulses
with a duration (T90) of 10.12 s measured from T0-0.46s.
The 500-ms peak rate, measured from T0-0.46 s, is 2948.6 cnts/sec.
The total counts from this burst is 23373.3 counts.


URL_LC: http://www.hxmt.org/images/GRB/HEB170826818_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 T0-1.00 to T0+9.00 s is
adequately fit by a Power Law model with spectral index = -2.03 +/- 0.04 . 
The energy fluence is (1.46 +/- 0.06)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.




--

Sincerely Yours,
Zhengwei Li,
Key Laboratory of Particle Astrophysics,
Institute of High Energy Physics, 
Chinese Academy of Sciences, Beijing China
TEL:15210983070 E-mail:lizw at ihep.ac.cn