GCN Circular 25171
Subject
LIGO/Virgo S190727h: possible counterpart candidate in SPI-ACS/INTEGRAL
Date
2019-07-27T14:26:04Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
P. Minaev (IKI), A. Pozanenko (IKI), I. Chelovekov (IKI), S. Grebenev
(IKI) on behalf of IKI GRB FuN collaboration report:
Using INTEGRAL/SPI-ACS public data we performed a search for
counterpart of S190727h (LVC, GCN 25164). We found only one significant
excess (3.6 sigma) at 4 sec and duration of 0.15 s after event time
2019-07-27T06:03:33.98. No more credible emission found within 100 s
after the trigger time of S190727h. The background excess variance 1.25
around +/-500 sec around event time which is somewhat higher than usual.
The significance of the excess will be further investigated by chance
coincidence analysis.
The fluence of the pulse is 574 +/- 160 counts which corresponds to
(5.7 +/ -1.6)*10^-8 erg/cm2 at the angle of 127 degrees toward most
probable area of localization. Assuming source distance of 2022.0 Mpc
this corresponds to the Eiso = (2.4 +/- 0.7)*10^49 erg.
The light curve of SPI-ACS can be found at
http://grb.rssi.ru/S190727h/S190727h_SPI-ACS_0.15s_LC.png