TITLE:   GCN CIRCULAR
NUMBER:  27206
SUBJECT: LIGO/Virgo S200225q: upper limits from AGILE/GRID observations
DATE:    20/02/25 16:23:18 GMT
FROM:    Francesco Verrecchia at SSDC,INAF-OAR  <francesco.verrecchia@ssdc.asi.it>

F. Verrecchia (SSDC, and INAF/OAR), A. Ursi (INAF/IAPS), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano
(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 S200225q at T0 = 2020-02-25
06:04:21.396 UTC a preliminary analysis of the AGILE exposure at T0 shows
that the Gamma-Ray Imaging Detector (GRID) exposure covered the 40% of the
90% c.l. localization region (LR; 39% of the 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 S200225q 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 9.8e-07 to 3.9e-06 erg cm^-2 s^-1, with exposure of about 40% of the
LR over the time interval (T0 - 2 s ; T0 + 2 s );
from 3.6e-07 to 1.1e-06 erg cm^-2 s^-1, with exposure of about 40% of the
LR over the time interval (T0 s ; T0 + 10 s);
from 3.0e-08 to 1.2e-07 erg cm^-2 s^-1, with exposure of about 40% of the
LR over the time interval (T0 s ; 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.