AGILE detection of prolonged and intense gamma-ray emission from Cygnus X-3
ATel #11814; G. Piano (INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), F. Verrecchia, C. Pittori, F. Lucarelli (SSDC and INAF/OAR), A. Ursi, M. Cardillo, G. Minervini (INAF/IAPS), A. Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/IASF-Bo), P. Munar-Adrover (UAB), I. Donnarumma (ASI), S. Vercellone (INAF/OA-Brera), E. Striani (CIFS and INAF/IAPS), M. Cardillo (INAF/IAPS), 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, M. Pilia, 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), S. Colafrancesco (INAF/OAR and Wits University), A. Ferrari (Univ. Torino and CIFS), F. Paoletti (East Windsor RSD Hightstown and INAF/IAPS), A. Antonelli, P. Giommi, L. Salotti, G. Valentini, and F. D'Amico (ASI)
on 4 Jul 2018; 14:15 UT
Credential Certification: Giovanni Piano (giovanni.piano@iaps.inaf.it)
Subjects: Gamma Ray, >GeV, Request for Observations, Binary, Black Hole, Transient
After the recent gamma-ray detection (ATel #11804), AGILE is detecting a prolonged gamma-ray emission above 100 MeV from a source positionally consistent with the microquasar Cygnus X-3. A preliminary multi-source likelihood analysis detects a peak gamma-ray flux F(>100 MeV) = (4.7 +/- 1.7) x 10^-6 photons/cm^2/s, integrating from 2018-07-02 UT 06:00:00 to 2018-07-04 UT 06:00:00.
The system is faint/undetected in the hard X ray band (Swift/BAT, 15-50 keV, count rate < 0.02 cts/cm^2/s) and shows a flickering activity at radio wavelengths (ATel #11805), which could represent a precursor ("hypersoft" state, Koljonen et al., 612, A27, 2018) of an incoming giant radio outburst.
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.
Multifrequency observations of Cygnus X-3 are strongly encouraged.
