AGILE detection of AGL J0813+2420, a new unidentified gamma-ray source.

ATel #2971; F. Lucarelli, F. Verrecchia (ASDC), E. Striani (Univ. Roma Tor Vergata and INFN Roma), S. Vercellone (INAF/IASF-Pa), C. Pittori (ASDC), M. Tavani (INAF/IASF-Rm, and Univ. Tor Vergata), A. Bulgarelli, F. Gianotti, M. Trifoglio (INAF/IASF-Bo), A. Chen, A. Giuliani, S. Mereghetti, P. Caraveo, F. Perotti (INAF/IASF-Mi), I. Donnarumma (INAF/IASF-Rm), F. D'Ammando (INAF/IASF-Pa), E. Del Monte, Y. Evangelista, M. Feroci, F. Lazzarotto, L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda, A. Argan, G. Piano, G. Pucella, S. Sabatini, A. Trois, V. Vittorini (INAF/IASF-Rm), F. Fuschino, M. Galli, C. Labanti, M. Marisaldi, G. Di Cocco (INAF/IASF-Bo), A. Pellizzoni, M. Pilia (INAF/OA-Cagliari), G. Barbiellini, F. Longo, E. Vallazza (INFN Trieste), A. Morselli, P. Picozza (INFN and Univ. Roma Tor Vergata), M. Prest (Universita` dell'Insubria), P. Lipari, D. Zanello (INFN and Univ. Roma Sapienza), P. W. Cattaneo, A. Rappoldi (INFN Pavia), P. Santolamazza, S. Colafrancesco, P. Giommi (ASDC), L. Salotti (ASI)
on 26 Oct 2010; 14:24 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: Fabrizio Lucarelli (fabrizio.lucarelli@asdc.asi.it)

Subjects: Gamma Ray, >GeV, Request for Observations, Transient

AGILE is detecting intense gamma-ray emission above 100 MeV from a new unidentified source, AGL J0813+2420, with Galactic coordinates (l, b) = (198.4, 28.1) +/- 0.5 deg (95% stat.) +/- 0.1 deg (syst.) (R.A.: 123.4, Dec.: 24.6, J2000).
Integrating from 2010-10-23 18:00 UT to 2010-10-26 06:00 UT, a maximum likelihood analysis yields a detection at a significance level above 5 sigma, and a flux of (260 +/- 80) x 10^-8 ph/cm2/s (E > 100 MeV).
No prominent extragalactic or Galactic gamma-ray source are known within the AGL J0813+2420 error circle. The source position is consistent with the flat spectrum radio source CRATES J0813+2435, which is about at 16 arcminutes from the emission peak.
This measurement was obtained with AGILE observing a large portion of the sky in a spinning mode.
Multifrequency observations of the AGL J0813+2420 error circle are strongly encouraged.