AGILE, Fermi, Swift, and GASP/WEBT multi-wavelength observations of the high-redshift blazar 4C +71.07 in outburst

59siContext. The flat-spectrum radio quasar 4C +71.07 is a high-redshift (z = 2.172), γ-loud blazar whose optical emission is dominated by thermal radiation from the accretion disc. Aims: 4C +71.07 has been detected in outburst twice by the AGILE γ-ray satellite during the period from the end of October to mid-November 2015, when it reached a γ-ray flux of the order of F(E > 100 MeV)=(1.2 ± 0.3)×10-6 photons cm-2 s-1 and F(E > 100 MeV)=(3.1 ± 0.6)×10-6 photons cm-2 s-1, respectively, allowing us to investigate the properties of the jet and the emission region. Methods: We investigated its spectral energy distribution by means of almost-simultaneous observations covering the cm, mm, near-infrared, optical, ultraviolet, X-ray, and γ-ray energy bands obtained by the GASP-WEBT Consortium and the Swift, AGILE, and Fermi satellites. Results: The spectral energy distribution of the second γ-ray flare (whose energy coverage is more dense) can be modelled by means of a one-zone leptonic model, yielding a total jet power of about 4 × 1047 erg s-1. Conclusions: During the most prominent γ-ray flaring period our model is consistent with a dissipation region within the broad-line region. Moreover, this class of high-redshift, flat-spectrum radio quasars with high-mass black holes might be good targets for future γ-ray satellites such as e-ASTROGAM.reservedmixedVercellone, S.*; Romano, P.; Piano, G.; Vittorini, V.; Donnarumma, I.; Munar-Adrover, P.; Raiteri, C.M.; Villata, M.; Verrecchia, F.; Lucarelli, F.; Pittori, C.; Bulgarelli, A.; Fioretti, V.; Tavani, M.; Acosta-Pulido, J.A.; Agudo, I.; Arkharov, A.A.; Bach, U.; Bachev, R.; Borman, G.A.; Butuzova, M.S.; Carnerero, M.I.; Casadio, C.; Damljanovic, G.; D'Ammando, F.; Di Paola, A.; Doroshenko, V.T.; Efimova, N.V.; Ehgamberdiev, S.A.; Giroletti, M.; Gómez, J.L.; Grishina, T.S.; Järvelä, E.; Klimanov, S.A.; Kopatskaya, E.N.; Kurtanidze, O.M.; Lähteenmäki, A.; Larionov, V.M.; Larionova, L.V.; Mihov, B.; Mirzaqulov, D.O.; Molina, S.N.; Morozova, D.A.; Nazarov, S.V.; Orienti, M.; Righini, S.; Savchenko, S.S.; Semkov, E.; Slavcheva-Mihova, L.; Strigachev, A.; Tornikoski, M.; Troitskaya, Y.V.; Vince, O.; Cattaneo, P.W.; Colafrancesco, S.; Longo, F.; Morselli, A.; Paoletti, F.; Parmiggiani, N.Vercellone, S.; Romano, P.; Piano, G.; Vittorini, V.; Donnarumma, I.; Munar-Adrover, P.; Raiteri, C. M.; Villata, M.; Verrecchia, F.; Lucarelli, F.; Pittori, C.; Bulgarelli, A.; Fioretti, V.; Tavani, M.; Acosta-Pulido, J. A.; Agudo, I.; Arkharov, A. A.; Bach, U.; Bachev, R.; Borman, G. A.; Butuzova, M. S.; Carnerero, M. I.; Casadio, C.; Damljanovic, G.; D'Ammando, F.; Di Paola, A.; Doroshenko, V. T.; Efimova, N. V.; Ehgamberdiev, S. A.; Giroletti, M.; Gómez, J. L.; Grishina, T. S.; Järvelä, E.; Klimanov, S. A.; Kopatskaya, E. N.; Kurtanidze, O. M.; Lähteenmäki, A.; Larionov, V. M.; Larionova, L. V.; Mihov, B.; Mirzaqulov, D. O.; Molina, S. N.; Morozova, D. A.; Nazarov, S. V.; Orienti, M.; Righini, S.; Savchenko, S. S.; Semkov, E.; Slavcheva-Mihova, L.; Strigachev, A.; Tornikoski, M.; Troitskaya, Y. V.; Vince, O.; Cattaneo, P. W.; Colafrancesco, S.; Longo, F.; Morselli, A.; Paoletti, F.; Parmiggiani, N