[vsnet-grb-info 23022] LIGO/Virgo S190720a: Upper limits from AGILE-GRID observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25121
SUBJECT: LIGO/Virgo S190720a: Upper limits from AGILE-GRID observations
DATE:    19/07/20 10:12:40 GMT
FROM:    Claudio Casentini at INAF-IAPS  <claudio.casentini at inaf.it>

C.Casentini (INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
M.Cardillo, G.Piano, 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), F. Longo
(Univ. Trieste, and INFN Trieste) report on behalf of the AGILE Team:

In response to the LIGO-Virgo GW event S190720a at T0 = 2019-07-20
00:08:36.747 (UT) a preliminary analysis of the AGILE exposure near T0
shows that the Gamma-Ray Imaging Detector (GRID) exposure covered about 44%
of the 90% c.l. localization region (LR).

We performed an analysis of the GRID data in the energy range 50 MeV - 10
GeV near T0. No candidate gamma-ray transient was detected.

The following preliminary GRID values of 3-sigma upper limit (UL) are
obtained:

from 8.68e-07 to 5.09e-06 erg cm^-2 sec^-1, during the time interval (T0 -
2 sec ; T0 + 2 sec);

from 3.36e-07 to 2.36e-06 erg cm^-2 sec^-1, during the time interval (T0 ;
T0 + 10 sec);

from 3.22e-08 to 2.34e-06 erg cm^-2 sec^-1, during the time interval (T0 ;
T0 + 100 sec).

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