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TITLE:   GCN CIRCULAR
NUMBER:  27454
SUBJECT: GRB 200326B: AstroSat LAXPC detection
DATE:    20/03/27 12:41:54 GMT
FROM:    Tilak Katoch at TIFR  <tilak@tifr.res.in>

H. M. Antia, Tilak Katoch, Parag Shah and Dhiraj Dedhia
TIFR, Mumbai, India.

Analysis of AstroSat LAXPC data showed the detection of a long
GRB 200326B. The light curve showed a double peak profile
triggered at T0 = 21h 13m 52s UT on 26 Mar 2020, with T90=10 sec
for the first peak followed by a second smaller peak of similar
duration about 10 s later. The measured peak count rate above the
background associated with the burst is 158 +/- 24 cts/s in
LAXPC10 and 171 +/- 20 cts/s in LAXPC20 at T0+3 sec. The total
counts in the first peak are 542 +/- 71 cts in LAXPC10 and
773 +/- 54 in LAXPC20.

Both LAXPC instruments (LAXPC10 and LAXPC20) have registered this
burst profile in the light curve. For LAXPC20 the nominal energy
range is 3-100 keV, but due to lower gain in LAXPC10 the energy
range is about 30-400 keV.

The background subtracted light curve with 1 sec time-bin is
available at the web-site:
https://www.tifr.res.in/~astrosat_laxpc/grb200326blc.jpg

LAXPC was built by TIFR in collaboration with the Indian Space
Research Organisation. The Indian Space Research Organisation
funded, managed and facilitated the project.

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TITLE:   GCN CIRCULAR
NUMBER:  27462
SUBJECT: GRB 200326B: AstroSat CZTI detection
DATE:    20/03/28 12:29:36 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (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 200326B, which was also detected by AstroSat LAXPC (Antia H. et al., GCN #27454). 

The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak of emission peaking at 2020-03-26 21:13:52 UT. The measured peak count rate associated with the burst is 146 +/- 23.5 cts/s above the background in the combined data of four quadrants, with a total of 354 +/- 10.6 cts. The local mean background count rate was 546 +/- 1.3 cts/s. Using cumulative rates, we measure a T90 of 8.1 +/- 0.6 s.

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.