[vsnet-grb-info 22475] LIGO-Virgo S190517h: AGILE GRID observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24574
SUBJECT: LIGO-Virgo S190517h: AGILE GRID observations
DATE:    19/05/17 09:17:52 GMT
FROM:    Francesco Verrecchia at ASDC  <francesco.verrecchia at ssdc.asi.it>

F. Verrecchia (SSDC, and INAF-OAR), G. Piano (INAF/IAPS),  M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), A. Ursi (INAF/IAPS), F. Lucarelli,
C. Pittori (SSDC, and INAF-OAR), M. Cardillo, C. Casentini,   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 S190517h at T0 = 2019-05-17 05:51:01.83
UTC (GCN #24570 including an updated localization) a preliminary analysis of
the AGILE exposure at T0 showed that the S190517h 90% c.l. localization region
(LR) was not exposed by the Gamma-Ray Imaging Detector (GRID).

We performed an analysis of the GRID data in the energy range 50 MeV -
10 GeV over two time intervals before and after T0, where good exposure of the
S190517h 90% c.l. LR was available. No candidate gamma-ray transient was
detected.

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

(T0-100s; T0 ): from 1.9e-07 to 7.9e-07 erg cm^-2 s^-1, with exposure of about
60% of the LR;

(T0+200s; T0 + 300s): from 4.5e-08 to 6.5e-07 erg cm^-2 s^-1, with exposure
of about 50% of the LR.

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