[vsnet-grb-info 23072] LIGO/Virgo S190727h: possible counterpart candidate in SPI-ACS/INTEGRAL

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25171
SUBJECT: LIGO/Virgo S190727h: possible counterpart candidate in SPI-ACS/INTEGRAL
DATE:    19/07/27 14:26:04 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at 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