{
  "bibcode": "2019GCN.24181....1C",
  "body": "I. Chelovekov, A. Pozanenko, P. Minaev, S. Grebenev on behalf of the IKI\nGRB FuN collaboration report:\n\nWe used public data (observations of Inner Galaxy, proposal 1620021, PI \nA. Bodaghee) of IBIS-ISGRI/INTEGRAL to search for a possible \nEM-counterpart of the LIGO/Virgo S190425z event (LVC GCN #24168). We \npresent our preliminary analysis of the prompt off-axis observation of \nthe event with IBIS-ISGRI.\n\nAround trigger time of S190425z (=G330561) the boresight angle was 30.8 \ndegrees. We found no significant emission above the background in the\ntime window -100 s + 100 s around the LIGO/Virgo S190425z trigger time.\n\nIn particular, we did not detect any positive signal near the time of a \nhard X-ray pulse detected by SPI-ACS/INTEGRAL(Martin-Carillo et al. GCN \n#24169; Minaev et al., GCN #24170; Savchenko et al., GCN #24178).\n\nThe upper limit of any possible emission with a duration of 1 s was (1.7 \n+/- 0.8) x 10^{-6} erg / cm2 and (1.3 +/- 0.8) x 10^{-6} erg / cm2 in \nthe energy ranges 30-100 and 100-500 keV, respectively. To estimate the \nflux we used our calibration based on several hundreds of GRBs \nsynchronously detected by GBM/Fermi and on/off-axis by IBIS/ISGRI \n(Chelovekov et al, 2019, in press).\n\nThe light curves of IBIS/ISGRI and SPI-ACS can be found in\n\nhttp://grb.rssi.ru/S190425z/S190425z_SPI-ACS.png\nhttp://grb.rssi.ru/S190425z/S190425z_IBIS_1s.png",
  "circularId": 24181,
  "createdOn": 1556201968000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "LIGO/Virgo S190425z: INTEGRAL IBIS prompt observation",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "LIGO/Virgo S190425z"
}