[vsnet-grb-info 24518] GRB 191227B: Insight-HXMT/HE observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26617
SUBJECT: GRB 191227B: Insight-HXMT/HE observation
DATE:    19/12/31 03:43:14 GMT
FROM:    Yunfei Du at IHEP  <duyunfei at ihep.ac.cn>

Y. F. Du, Y. G. Zheng, C. Cai, Q. Luo, S. Xiao, Q. B. Yi, 
Y. Huang, C. K. Li, G. Li, X. B. 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:

At 2019-12-27T17:21:44.14 (T0), Insight-HXMT/HE detected 
GRB 191227B (trigger ID: HEB191227723) in a routine search of the data, 
which was also triggered by Fermi/GBM, IPN and Konus-Wind (GCN #26612).

The Insight-HXMT/HE light curve mainly consists of multiple 
pulses with a duration (T90) of 0.161 s measured from T0+0.010 s. 
The 1-ms peak rate, measured from T0+0.045 s, is 50,544 cnts/sec. 
The total counts from this burst is 4123 counts. But it should be
noted that the Insight-HXMT/HE detection suffers from saturation 
when the count rate exceeds ~20,000 cnts/sec. The uncorrected 
light curve can be found at:
URL_LC: http://www.hxmt.org/images/GRB/HEB191227723_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 (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 telescope. 

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.