GCN Circular 24071
Subject
LIGO-Virgo S190408an: AGILE GRID observations
Date
2019-04-09T00:14:47Z (6 years ago)
From
Fabrizio Lucarelli at SSDC/INAF-OAR <fabrizio.lucarelli@ssdc.asi.it>
F. Lucarelli, C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS), A. Bulgarelli, 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 trigger event S190408an at
T0 = 2019-04-08 18:18:02 (UT) (GCN #24069) we performed an
analysis of the AGILE Gamma-Ray Imaging Detector (GRID) data.
At LIGO/Virgo trigger time (T0) the GRID exposure did not optimally cover the
LIGO/Virgo localization region.
An analysis of the data in the energy range 30 MeV - 10 GeV was performed
over the time intervals T0-300s -- T0-200s, where full coverage of the majority of the
localisation region was reached.
Preliminary values of 3-sigma upper limits (UL) obtained within the accessible
LIGO/Virgo 90% c.l. localization region over this time interval are in the range:
from 2.0e-07 to 6.5e-07 erg cm^-2 s^-1 for an integration time of 100s.
For an integration time of 200s which includes T0, preliminary 3-sigma ULs are
in the range:
from 5.0e-08 to 3.0e-07 erg cm^-2 s^-1,
with a lower localization region coverage of about 80%.
These measurements were obtained with AGILE observing a large portion of the
sky in spinning mode. Additional analysis of AGILE data is in progress.