The mid-2016 flaring activity of the flat spectrum radio quasar PKS 2023-07
Via del Fosso del Cavaliere 100,
2 CIFS, c/o Dipartimento di Fisica, Università di Torino, Via P. Giuria 1, 10125 Torino, Italy
3 Unitat de Física de les Radiacions, Departament de Física and CERES-IEEC, Universitat Autónoma de Barcelona, 08193 Bellaterra, Spain
4 INAF, Osservatorio Astronomico di Brera, Via E. Bianchi 46, 23807 Merate, Italy
5 ASI, Via del Politecnico snc, 00133 Roma, Italy
6 Space Science Data Center/ASI (SSDC), Via del Politecnico, 00133 Roma, Italy
7 INAF-OAR, Via Frascati 33, 00078 Monte Porzio Catone, Roma, Italy
8 Instituto Nacional de Astrofisica Optica y Electronica (INAOE), Apartado Postal 51 y 216, 72000 Puebla, Mexico
9 Astronomia, Accademia Nazionale dei Lincei, Via della Lungara 10, 00165 Roma, Italy
10 Università “Tor Vergata”, Dipartimento di Fisica, Via della Ricerca Scientifica 1, 00133 Roma, Italy
11 Gran Sasso Science Institute, Viale Francesco Crispi 7, 67100 L’Aquila, Italy
Accepted: 12 May 2018
Context. Flat spectrum radio quasars (FSRQs) can suffer strong absorption above E = 25∕(1 + z) GeV, due to gamma–gamma interaction if the emitting region is at sub-parsec scale from the super-massive black hole (SMBH).
Aims. Gamma-ray flares from these astrophysical sources can be used to investigate the location of the high-energy emission region and the physics of the radiating processes.
Methods. We present an episode of remarkable gamma-ray flaring activity from FSRQ PKS 2023-07 during April 2016, as detected by both the AGILE and Fermi satellites. An intensive multiwavelength campaign, triggered by Swift, covered the entire duration of the flaring activity, including the peak gamma-ray activity.
Results. We report the results of multiwavelength observations of the blazar. We found that during the peak emission, the most energetic photon had an energy of 44 GeV, putting strong constraints on the opacity of the gamma-ray dissipation region. The overall spectral energy distribution (SED) is interpreted in terms of leptonic models for blazar jets, with the emission site located beyond the broad line region (BLR).
Key words: galaxies: active / quasars: general / quasars: supermassive black holes
© ESO 2018