TITLE:   GCN CIRCULAR
NUMBER:  24165
SUBJECT: LIGO-Virgo S190421ar:Insight-HXMT/HE observation
DATE:    19/04/25 02:56:19 GMT
FROM:    Shuo Xiao at IHEP  <xiaoshuo@ihep.ac.cn>

S. Xiao, C. K. Li, X. B. Li, G. 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: 

In response to the LIGO-Virgo GW event S190421ar T0 = 2019-04-21 
21:38:56 (UTC; GCN #24141), analysis of HXMT/HE data shows that the 
satellite at T0 was in the South Atlantic Anomaly (SAA).

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 could be found at: http://www.hxmt.org.