GCN Circular 26338

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

In response to the LIGO-Virgo GW event S191204r at T0 = 2019-12-04
17:15:26.092 UTC a preliminary analysis of the AGILE exposure at T0 shows
that the Gamma-Ray Imaging Detector (GRID) exposure covered less than 10%
of the 90% c.l. localization region (LR) (16% of 90% c.l. localization
region (LR) is occulted by Earth).

We performed an analysis of the GRID data in the energy range 50 MeV - 10
GeV on T0, where good exposure of the S191204r 90% c.l. LR was available.

No candidate gamma-ray transient was detected.

The following preliminary GRID values of 3-sigma upper limit (UL) are
obtained:
from 3.5e-08 to 9.0e-07 erg cm^-2 s^-1, with exposure of about 65% of the
LR over the time interval (T0; T0 + 100 s);

These measurements were obtained with AGILE observing a large portion of
the sky in spinning mode. Additional analysis of AGILE data is in progress.