GCN Circular 27694
Subject
GRB 200422A: INTEGRAL observations
Event
Date
2020-05-06T17:09:03Z (6 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@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