{
  "bibcode": "2019GCN.24728....1O",
  "body": "F. Onori (IAPS-Roma, Italy),\nV. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)\nJ. Rodi (IAPS-Roma, Italy)\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 Savchenko\net al. 2017, A&A 603, A46): SPI/ACS, IBIS/Veto, and IBIS  we have\nperformed a search for a prompt gamma-ray counterpart of S190602aq\n(GCN 24717).\n\nAt the time of the event (2019-06-02 17:59:27 UTC, hereafter T0),\nINTEGRAL was operating in nominal mode. The peak of the event\nlocalization probability was at an angle of 128 deg with respect to\nthe spacecraft pointing axis. This orientation implies strongly\nsuppressed (3.9% of optimal) response of ISGRI, somewhat suppressed\n(56% of optimal) response of IBIS/Veto, and strongly suppressed (29%\nof optimal) response of 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-\nACS (as described in Savchenko et al. 2012, A&A 541A, 122S), IBIS, and\nIBIS/Veto data.\n\nWe do not detect any significant counterparts and estimate a 3-sigma\nupper limit on the 75-2000 keV fluence of 3.8e-07 erg/cm^2 (within the\n50% probability containment 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 ~3.7e-07 (1.2e-07)\nerg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range.\n\n-- \nDr. Francesca Onori\nPostdoctoral Researcher\nIAPS, via Fosso del Cavaliere, 100, 00133 - Rome, Italy\ne-mail: francesca.onori@inaf.it\nTel: +39 06 45488128",
  "circularId": 24728,
  "createdOn": 1559551854000,
  "email": "francesca.onori@inaf.it",
  "subject": "LIGO/Virgo S190602aq: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation",
  "submitter": "Francesca Onori at INAF/IAPS  <francesca.onori@inaf.it>",
  "eventId": "LIGO/Virgo S190602aq"
}