{
  "bibcode": "2019GCN.25821....1V",
  "body": "F. Verrecchia (SSDC, and INAF/OAR), C. Casentini (INAF/IAPS), M. Tavani\n(INAF/IAPS, and Univ.Roma Tor Vergata), M. Cardillo, G. Piano, A. Ursi\n(INAF/IAPS), F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), A.\nBulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia\n(INAF/OA-Cagliari), F. Longo (Univ. Trieste, and INFN Trieste) report on\nbehalf of the AGILE Team:\n\nIn response to the LIGO-Virgo GW event S190923y at T0 = 2019-09-23\n12:55:59.646 UTC a preliminary analysis of the AGILE exposure at T0\nshows that the Gamma-Ray Imaging Detector (GRID) exposure covered the 10%\nof the 90% c.l. localization region (LR) (40% of 90% c.l. localization\nregion (LR) is occulted by Earth) at an off-axis angle of about 5\ndegrees.\n\nWe performed an analysis of the GRID data in the energy range 50 MeV -\n10 GeV on T0, where good exposure of the S190923y 90% c.l. LR was\navailable.\n\nNo candidate gamma-ray transient was detected.\n\nThe following preliminary GRID values of 3-sigma upper limit (UL) are\nobtained:\n- from 7.0e-07 to 9.3e-07 erg cm^-2 s^-1, with exposure of about 10% of\nthe LR over the time interval ( T0 - 2s ; T0 + 2s );\n- from 2.9e-07 to 4.2e-07 erg cm^-2 s^-1, with exposure of about 10% of\nthe LR over the time interval ( T0 ; T0 + 10s );\n- from 6.5e-08 to 6.6e-06 erg cm^-2 s^-1, with exposure of about 11% of\nthe LR over the time interval ( T0 ; T0 + 100s ) ;\n\nA map in Galactic coordinates showing the AGILE FoV at T0 is available\nat the site:\nhttps://tools.ssdc.asi.it/ImgView/Agile/AGILE_FOV_LIGO-VirgoS190923y_1909232521\n\nThese measurements were obtained with AGILE observing a large portion of\nthe sky in spinning mode. Additional analysis of AGILE data is in progress.\n\n\n\n==========================================================================\nFrancesco Verrecchia\nASDC - ASI Science Data Center -\nINAF/OAR - Istituto Nazionale di Astrofisica/\n           Osservatorio Astronomico di Roma -\n\nc/o ASI - Agenzia Spaziale Italiana -\nvia del Politecnico snc, I-00133, Roma  - Italy\n==========================================================================\ne-mail:francesco.verrecchia@ssdc.asi.it\nphone:+39 068567 882\ne-mail OAR:francesco.verrecchia@oa-roma.inaf.it\n==========================================================================",
  "circularId": 25821,
  "createdOn": 1569253670000,
  "email": "francesco.verrecchia@ssdc.asi.it",
  "subject": "LIGO/Virgo S190923y: Upper limits from AGILE-GRID observations",
  "submitter": "Francesco Verrecchia at ASDC  <francesco.verrecchia@ssdc.asi.it>",
  "eventId": "LIGO/Virgo S190923y"
}