TITLE:   GCN CIRCULAR
NUMBER:  25840
SUBJECT: LIGO/Virgo S190924h: no counterpart candidates in AGILE-GRID observations
DATE:    19/09/24 09:14:06 GMT
FROM:    Giovanni Piano at INAF-IAPS  <giovanni.piano@inaf.it>

G. Piano, M. Cardillo (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), M.
Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), C. Casentini, A. Ursi
(INAF/IAPS), F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), A. Bulgarelli,
V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia
(INAF/OA-Cagliari), F. Longo (Univ. Trieste, and INFN Trieste), report on
behalf of the AGILE Team:

In response to the LIGO-Virgo GW event S190924h at T0 =  2019-09-24
02:18:46.847 UTC, a preliminary analysis of the AGILE data at T0 shows that
the Gamma-Ray Imaging Detector (GRID) has no exposure of the 90% c.l.
localization region (LR).

The closest exposure in time occurred at T0 - 400 s, covering about 40% of
the LR. We performed an analysis of the GRID data in the energy range 50
MeV - 10 GeV. The following preliminary GRID 3-sigma upper limit (UL) value
is obtained over the exposed region of the LR:

from 7.7e-08 to 3.0e-07 erg cm^-2 s^-1, over the time interval (T0 - 400 s;
T0 - 300 s).

This measurement was obtained with AGILE observing a large portion of the
sky in spinning mode. Additional analysis of AGILE data is in progress.