{
"subject": "LIGO/Virgo S190707q: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observations",
"bibcode": "2019GCN.25029....1S",
"createdOn": 1562570369000,
"circularId": 25029,
"submitter": "Celia Sanchez-Fernandez at ISOC/ESA ",
"email": "Celia.Sanchez@sciops.esa.int",
"body": "Celia Sanchez-Fernandez (ESA/ESAC, Spain), James Rodi (IAPS-Roma, Italy)\nV. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)\nA. Coleiro (APC, France)\nS. Mereghetti (INAF IASF-Milano, Italy)\n\non behalf of the INTEGRAL multi-messenger collaboration:\nhttps://www.astro.unige.ch/cdci/integral-multimessenger-collaboration\n\nUsing combination of INTEGRAL all-sky detectors (following [1]):\nSPI/ACS, IBIS/Veto, and IBIS we have performed a search for a prompt\ngamma-ray counterpart of S190707q (GCN 25012).\n\nAt the time of the event (2019-07-07 09:33:26 UTC, hereafter T0),\nINTEGRAL was operating in nominal mode. The peak of the event\nlocalization probability was at an angle of 169 deg with respect to\nthe spacecraft pointing axis. This orientation implies strongly\nsuppressed (3.3% of optimal) response of ISGRI, near-optimal (88% of \noptimal)\nresponse of IBIS/Veto, and strongly suppressed (38% of optimal) response\nof SPI-ACS.\n\nThe background within +/-300 seconds around the event was very stable\n(excess variance 1.1).\n\nWe have performed a search for any impulsive events in INTEGRAL SPI-ACS\n(as described in [2]), IBIS, and IBIS/Veto data.\n\nWe do not detect any significant counterparts and estimate a 3-sigma\nupper limit on the 75-2000 keV fluence of 2.6e-07 erg/cm^2 (within the\n50% probability containement region of the source localization) for a\nburst lasting less than 1 s with a characteristic short GRB spectrum\n(an exponentially cut off power law with alpha=-0.5 and Ep=600 keV)\noccurring at any time in the interval within 300 s around T0. For a\ntypical long GRB spectrum (Band function with alpha=-1, beta=-2.5, and\nEp=300 keV), the derived peak flux upper limit is ~2.1e-07 (6.4e-08)\nerg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range.\n\nFor the mean reported distance 810.0 Mpc this corresponds to the limit\non the total isotropic equivalent energy in 1 s of 2e+49 erg for the\nshort GRB spectrum and for a long GRB spectrum isotropic equivalent\nluminosity in 1 s (8 s) of 1.7e+49 erg/s (5.1e+48 erg/s)\n\nAll results quoted are preliminary.\n\nThis circular is an official product of the INTEGRAL Multi-Messenger team.\n\n[1] Savchenko et al. 2017, A&A 603, A46\n[2] Savchenko et al. 2012, A&A 541A, 122S\n\n\n\nThis message is intended only for the recipient(s) named above. It may contain proprietary information and/or\nprotected content. Any unauthorised disclosure, use, retention or dissemination is prohibited. If you have received\nthis e-mail in error, please notify the sender immediately. ESA applies appropriate organisational measures to protect\npersonal data, in case of data privacy queries, please contact the ESA Data Protection Officer (dpo@esa.int)."
}