TITLE: GCN CIRCULAR NUMBER: 25029 SUBJECT: LIGO/Virgo S190707q: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observations DATE: 19/07/08 07:19:29 GMT FROM: Celia Sanchez-Fernandez at ISOC/ESA Celia Sanchez-Fernandez (ESA/ESAC, Spain), James Rodi (IAPS-Roma, Italy) V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland) A. Coleiro (APC, France) S. Mereghetti (INAF IASF-Milano, Italy) on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration Using combination of INTEGRAL all-sky detectors (following [1]): SPI/ACS, IBIS/Veto, and IBIS we have performed a search for a prompt gamma-ray counterpart of S190707q (GCN 25012). At the time of the event (2019-07-07 09:33:26 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 169 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (3.3% of optimal) response of ISGRI, near-optimal (88% of optimal) response of IBIS/Veto, and strongly suppressed (38% of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was very stable (excess variance 1.1). We have performed a search for any impulsive events in INTEGRAL SPI-ACS (as described in [2]), IBIS, and IBIS/Veto data. We do not detect any significant counterparts and estimate a 3-sigma upper limit on the 75-2000 keV fluence of 2.6e-07 erg/cm^2 (within the 50% probability containement region of the source localization) for a burst lasting less than 1 s with a characteristic short GRB spectrum (an exponentially cut off power law with alpha=-0.5 and Ep=600 keV) occurring at any time in the interval within 300 s around T0. For a typical long GRB spectrum (Band function with alpha=-1, beta=-2.5, and Ep=300 keV), the derived peak flux upper limit is ~2.1e-07 (6.4e-08) erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range. For the mean reported distance 810.0 Mpc this corresponds to the limit on the total isotropic equivalent energy in 1 s of 2e+49 erg for the short GRB spectrum and for a long GRB spectrum isotropic equivalent luminosity in 1 s (8 s) of 1.7e+49 erg/s (5.1e+48 erg/s) All results quoted are preliminary. This circular is an official product of the INTEGRAL Multi-Messenger team. [1] Savchenko et al. 2017, A&A 603, A46 [2] Savchenko et al. 2012, A&A 541A, 122S This message is intended only for the recipient(s) named above. It may contain proprietary information and/or protected content. Any unauthorised disclosure, use, retention or dissemination is prohibited. If you have received this e-mail in error, please notify the sender immediately. ESA applies appropriate organisational measures to protect personal data, in case of data privacy queries, please contact the ESA Data Protection Officer (dpo@esa.int).