GCN Circular 32303
Subject
GRB 220624A: AGILE/GRID refined analysis
Date
2022-06-30T14:30:05Z (3 years ago)
From
Francesco Verrecchia at SSDC,INAF-OAR <francesco.verrecchia@ssdc.asi.it>
F. Verrecchia (SSDC, and INAF/OAR), A. Ursi (INAF/IAPS), A. Giuliani
(INAF/IASF-Mi), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
F. Longo (Univ. Trieste and INFN Trieste), L. Foffano (INAF/IAPS),
F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), M. Romani
(INAF/OA-Brera), G. Piano, A. Argan, M. Cardillo, C. Casentini,
Y. Evangelista, E. Menegoni (INAF/IAPS), A. Bulgarelli, A. Di Piano,
V. Fioretti, N. Parmiggiani (INAF/OAS), M. Marisaldi (INAF/OAS,
and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari),
I. Donnarumma (ASI), and P. Tempesta (TeleSpazio), report on
behalf of the AGILE Team:
he Gamma-Ray Imaging Detector (GRID) of AGILE detected gamma-ray
transient emission consistent with the long GRB 220624A reported
by Fermi/GBM (GCN #32256) at T0 = 2022-06-24 02:58:35 s (UTC),
as already reported in Verrecchia et al. GCN #32261 and also
detected by AGILE/MCAL (Ursi et al., GCN #32259).
An improved localization has been reported by the IPN (Kozyrev
et al. GCN #32265).
A refined AGILE/GRID data analysis in the energy range 30 MeV - 10
GeV shows a detection with a statistical significance of about 10
sigma over a time integration of 20 s starting at the T0 of GRB
220624A, at a sky position with Galactic coordinates l=260 deg,
b=75 deg, with and an error radius of 4 deg (90% statistical +
systematic error; R.A.= 182 deg, Decl.= 16 deg (J2000)).
The GRID error circle includes the IPN position.
During the 20s integration, we detected a total of 41 events (3
background events estimated through a Li&Ma analysis), 17 events at
energies above 100 MeV, and 3 events above 1 GeV.
These measurements were obtained with AGILE observing a large
portion of the sky in spinning mode. Additional analysis of AGILE
data is in progress.