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TITLE:   GCN CIRCULAR
NUMBER:  24117
SUBJECT: GRB 190411A: Insight-HXMT/HE detection
DATE:    19/04/13 12:22:06 GMT
FROM:    Ce Cai at IHEP  <caice@ihep.ac.cn>

C. Cai, 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: 

At 2019-04-11T09:45:46.000 (T0), the Insight-HXMT/HE detected 
GRB 190411A (trigger ID: HEB190411406) in a routine search of the data, 
which was also triggered by Fermi/GBM (trigger number 576668753);

The Insight-HXMT/HE light curve mainly consists of multiple 
pulses with a duration (T90) of 34.10 s measured from T0+2.32 s. 
The 1-s peak rate, measured from T0+4.50 s, is 19416 cnts/s. 
The total counts from this burst is 110320 counts. 
URL_LC: http://www.hxmt.org/images/GRB/HEB190411406_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. 

Insight-HXMT is the first Chinese space X-ray telescope, which was 
fundedjointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information could be found at: http://www.hxmt.org.

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TITLE:   GCN CIRCULAR
NUMBER:  24118
SUBJECT: GRB 190411A: AstroSat CZTI detection
DATE:    19/04/13 13:57:05 GMT
FROM:    Tanazza Khanam at IUCAA  <tanazza@iucaa.in>

T. Khanam, V. Sharma, D. Bhattacharya and A. Vibhute (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 190411A, which was also detected by Insight-HXMT/HE detection (Cai C. et al., GCN # 24117).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple pulses of emission with strongest peak at 09:45:52.5 UT. The measured peak count rate associated with the burst is 3857.37 cts/s above the background in the combined data of four quadrants, with a total of 40446 cts. The local mean background count rate was 321.6 cts/s. Using cumulative rates, we measure a T90 of 42.7 s. In preliminary analysis, we find that 3004 Compton events are associated with this event.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.