[vsnet-grb-info 24474] GRB 191221B: Insight-HXMT/HE detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26573
SUBJECT: GRB 191221B: Insight-HXMT/HE detection
DATE:    19/12/24 08:16:39 GMT
FROM:    Wangchen Xue at IHEP  <xuewc at ihep.ac.cn>

W. C. Xue, 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 2019-12-21T20:39:10.70 (T0), Insight-HXMT/HE detected 
GRB 191221B (trigger ID: HEB191221860) in a routine search of the data, 
which was also triggered by Swift/BAT (GCN #26534).

The Insight-HXMT/HE light curve mainly consists of multiple  
pulses with a duration (T90) of 8.85 s measured from T0-0.62 s. 
The 1-ms peak rate, measured from T0+5.37 s, is 8262 cnts/sec. 
The total counts from this burst is 38429 counts. 
URL_LC: http://www.hxmt.org/images/GRB/HEB191221860_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.