[vsnet-grb-info 25594] GRB 200422A: INTEGRAL observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27694
SUBJECT: GRB 200422A: INTEGRAL observations
DATE:    20/05/06 17:09:03 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

P. Minaev (IKI), I. Chelovekov (IKI), A. Pozanenko (IKI), S. Grebenev 
(IKI) report on behalf of GRB IKI FuN:

We analyzed publically available data of SPI-ACS detector onboard the 
INTEGRAL observatory. GRB 200422A (Hurley et al., GCN 27626; Gupta et 
al., GCN 27630; Svinkin et al., GCN 27635) did not trigger IBAS 
(http://ibas.iasf-milano.inaf.it/).

The GRB 200422A is detected in SPI-ACS data as very intense burst at 
(UTC) 2020-04-22T07:22:03.1. The T_90 duration of the burst is 12.3 +/- 
0.1 s in SPI-ACS. The fluence in 10-1000 keV energy band is 3.62e-4 
erg/cm2 with statistical error of 5e-6 erg/cm2 (1.0e-4 — 1.2e-3 ergs/cm2 
in the 95% confident region, including systematics)  as defined after 
calibration based on long duration GRBs (Chelovekov et al., in 
preparation). We do not detect significant precursor in any 0.1 – 5 sec 
time scale within 500 s prior to the trigger. Probable extended emission 
is detected up to 250 s after the trigger.

The light curve can be found at 
http://grb.rssi.ru/GRB200422A/GRB200422A_SPI-ACS_LC.png

We also put the spectral data of GRB 200422A reported  by Konus-Wind 
(Svinkin et al., GCN 27635) onto E_iso -- E_p diagram (AKA Amati 
relation, see also Minaev et al., MNRAS, 492, 1919 (2020).

A GRB 200422A trajectory of parameters E_iso,i -- E_p,i  along redshift 
restricts the redshift of GRB 200422A  as 2 > z > 0.1, see figure at

http://grb.rssi.ru/GRB200422A/GRB200422A_Ep-Eiso_diagram.png