AGILE detection of a rebrightening of the gamma-ray source AGL J2251-1239
ATel #11127; G. Piano (INAF/IAPS), C. Pittori (SSDC and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), F. Lucarelli, F. Verrecchia (SSDC and INAF/OAR), P. Giommi (ASI), M. Cardillo, A. Ursi, G. Minervini (INAF/IAPS), A. Bulgarelli, N. Parmiggiani (INAF/IASF-Bo), S. Vercellone (INAF/OA-Brera), V. Fioretti (INAF/IASF-Bo), M. Pilia (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Gianotti, M. Trifoglio (INAF/IASF-Bo), A. Giuliani, S. Mereghetti, P. Caraveo, F. Perotti (INAF/IASF-Mi), A. Chen (Wits University), A. Argan, E. Costa, E. Del Monte, Y. Evangelista, M. Feroci, F. Lazzarotto, I. Lapshov, L. Pacciani, P. Soffitta, S. Sabatini, V. Vittorini (INAF/IAPS), G. Pucella, M. Rapisarda (ENEA-Frascati), G. Di Cocco, F. Fuschino, M. Galli, C. Labanti, M. Marisaldi (INAF/IASF-Bo), A. Pellizzoni, A. Trois (INAF/OA-Cagliari), G. Barbiellini, E. Vallazza (INFN Trieste), F. Longo (Univ. Trieste and INFN Trieste), A. Morselli, P. Picozza (INFN and Univ. Roma Tor Vergata), M. Prest (Univ. dell'Insubria), P. Lipari, D. Zanello (INFN and Univ. Roma Sapienza), P. W. Cattaneo, A. Rappoldi (INFN Pavia), A. Ferrari (Univ. Torino and CIFS), S. Colafrancesco (INAF/OAR and Wits University), F. Paoletti (East Windsor RSD Hightstown and INAF/IAPS), A. Antonelli (SSDC), L. Salotti, G. Valentini, and F. D'Amico (ASI)
on 4 Jan 2018; 21:59 UT
Credential Certification: Giovanni Piano (giovanni.piano@iaps.inaf.it)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar, Quasar
AGILE is detecting again intense gamma-ray emission above 100 MeV from a source at Galactic coordinates (l, b) = (54.6, -58.4) +/- 0.9 deg (95% stat. c.l.) +/- 0.1 deg (syst.) (R.A., Dec. (J2000): 342.26, -12.74 deg), compatible with AGL J2251-1239 reported in a flaring state by AGILE on December 8, 2017 (ATel #11043, F. Lucarelli et al.).
Integrating from 2018-01-02 08:00 UT to 2018-01-04 08:00 UT, a preliminary maximum likelihood analysis yields a detection above 5 sigma and a flux F(E>100 MeV) = (2.8 +/- 0.9) x 10^-6 ph cm^-2 s^-1.
The unassociated gamma-ray source 3FGL J2253.1-1237 and the blazars PKS 2247-131, 5BZB J2249-1300, and 5BZQ J2247-1237 are inside the 95% c.l. AGILE error region, whereas the blazar PKS 2243-123 is within the 99% c.l. AGILE error region.
This measurement was obtained with AGILE observing a large portion of the sky in spinning mode. Multifrequency observations of AGL J2251-1239 are strongly encouraged.
