Ongoing gamma-ray flare from the blazar PKS 1424-418 detected by AGILE
ATel #15527; G. Piano (INAF/IAPS), G. Panebianco (Univ. Bologna - INAF/OAS-Bo), C. Pittori, F. Verrecchia (SSDC and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Bulgarelli, V. Fioretti, N. Parmiggiani, A. Addis, L. Baroncelli, A. Di Piano (INAF/OAS-Bo), F. Lucarelli (SSDC and INAF/OAR), S. Vercellone (INAF/OA-Brera), M. Cardillo, A. Ursi, C. Casentini (INAF/IAPS), I. Donnarumma (ASI), F. Gianotti, M. Trifoglio (INAF/OAS-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, L. Foffano, I. Lapshov, E. Menegoni, L. Pacciani, P. Soffitta, V. Vittorini (INAF/IAPS), F. Lazzarotto (INAF/OAPD), G. Di Cocco, F. Fuschino, M. Galli, C. Labanti (INAF/OAS-Bo), M. Marisaldi (University of Bergen), A. Pellizzoni, M. Pilia, A. Trois (INAF/OA-Cagliari), G. Barbiellini (INFN Trieste), F. Longo (Univ. Trieste and INFN Trieste), E. Vallazza (INFN Milano Bicocca), 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), F. Paoletti (East Windsor RSD Hightstown and INAF/IAPS), L. A. Antonelli (INAF/OAR), P. Giommi, L. Salotti, G. Valentini, and F. D'Amico (ASI)
on 25 Jul 2022; 10:48 UT
Credential Certification: Giovanni Piano (giovanni.piano@inaf.it)
Subjects: Gamma Ray, >GeV, AGN, Blazar, Quasar
The GRID detector onboard the AGILE satellite is detecting a bright gamma-ray flare from the blazar PKS 1424-418 (z = 1.522, White et al., ApJ 327 561, 1988). The onset of a bright optical/GeV flare from this source has been previously reported a few days ago (ATel #15525). Integrating from 2022-07-22 UT 06:00:00 to 2022-07-25 UT 06:00:00, a preliminary multi-source likelihood analysis yields a detection with a significance of about 6 sigma and a gamma-ray flux F(>100 MeV) = (2.9 +/- 0.8) x 10^-6 photons/cm^2/s. The average flux, detected by the AGILE-GRID during the previous 7 days, was F(>100 MeV) = (1.4 +/- 0.4) x 10^-6 photons/cm^2/s. Multifrequency observations of this blazar are strongly encouraged.
The AGILE-GRID detection was obtained while AGILE is observing in spinning mode, surveying a large fraction of the sky each day. The source can be monitored with the public mobile application "AGILEScience" developed by the AGILE Team, available for both Android and iOS devices.
