Multi-wavelength observations of the high-redshift blazar 4C+71.07

Abstract

The flat-spectrum radio quasar 4C+71.07 has been detected by the AGILE gamma-ray satellite on 2015 October 27-29 and 2015 November 08-10, when it reached a gamma-ray flux ({E}>100 MeV) of the order of 1.2 × 10^{-6} ph cm^{-2} s^{-1} and 3.1 × 10^{-6} ph cm^{-2} s^{-1}, respectively. Because of its relatively high redshift (z=2.172), this blazar shows a prominent accretion disc bump peaking in the ultra-violet band, which makes this source an excellent candidate to investigate not only the jet emission but also the non thermal one. We investigated its spectral energy distribution by means of almost simultaneous observations covering the cm, mm, near-infrared, optical, ultra-violet, X-ray and gamma-ray energy bands obtained by the GASP-WEBT Consortium, Swift, and AGILE satellites. We present the spectral energy distribution of the gamma-ray flare whose energy coverage is more dense, modelling it by means of a one-zone leptonic model.