GCN Circular 21064
Subject
LIGO/Virgo G284239: AGILE GRID observations
Date
2017-05-03T21:13:36Z (7 years ago)
From
Francesco Verrecchia at ASDC, INAF-OAR <verrecchia@asdc.asi.it>
G. Minervini (INAF/IAPS), C. Pittori (ASDC), M. Pilia (INAF/OA-Cagliari),
M. Cardillo (INAF/IAPS), F. Verrecchia (ASDC and INAF/OAR),
M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), G. Piano (INAF/IAPS),
A. Bulgarelli, V. Fioretti, A. Zoli, N. Parmiggiani (INAF/IASF-Bo),
F. Lucarelli (ASDC and INAF/OAR), P. Munar-Adrover (INAF/IAPS), A.
Argan, Y. Evangelista (INAF/IAPS), I. Donnarumma (ASI), F. Fuschino, M.
Marisaldi (INAF/IASF-Bo and Bergen University), A. Giuliani (INAF/IASF-Mi),
A. Trois (INAF/OA-Cagliari), F. Longo (Univ. Trieste and INFN Trieste),
report on behalf of the AGILE Team:
In response to the LIGO/Virgo event G284239 (GCN #21060) we performed an
analysis of the AGILE Gamma-Ray Imaging Detector (GRID) data on different
timescales.
On LIGO trigger time (T0 = 2017-05-02 22:26:07.910 UT) the GRID had no
exposure of the the LVC localization region (LR) mainly due to Earth
occultation. The GRID large-FoV covered about 25-35% of the LR on
integrations
from about T0-100s to T0, and from T0+300s to T0+400s following the T0,
with
off-axis angles between 20 and 70 deg, approximately.
An analysis of the GRID data in the energy range 50 MeV - 10 GeV was
performed on timescales from 2 to 100 sec centered at T0-50s. Preliminary
minimum and maximum values of 3-sigma upper limits obtained within the
accessible G284239 LR are reported below:
from 1.4e-07 erg cm^-2 s^-1 to 6.5e-07 erg cm^-2 s^-1 for an integration
time
of 20s, and from 3.2e-08 erg cm^-2 s^-1 to 2.5e-07 erg cm^-2 s^-1 for an
integration time of 100s.
These measurements were obtained with AGILE observing a large portion of
the sky in spinning mode. Additional analysis of AGILE data is in progress.