A two-component model for the high-energy variability of blazars

Application to PKS 2155-304

¹ Instituto de Investigaciones Físicas de Mar del Plata (CONICET – UNMdP), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Dean Funes 3350, (7600) Mar del Plata, Argentina
e-mail: mreynoso@mdp.edu.ar
² Instituto Argentino de Radioastronomía, CCT La Plata-CONICET, 1894, Villa Elisa C.C. No. 5, Argentina
³ Irfu, Service de Physique des Particules, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France

Received: 22 June 2012
Accepted: 11 August 2012

Abstract

Aims. We study the production of very-high-energy emission in blazars as a superposition of a steady component from a baryonic jet and a time-dependent contribution from an inner e⁻e⁺ beam launched by the black hole.

Methods. Both primary relativistic electrons and protons are injected in the jet, and the particle distributions along it are found by solving a one-dimensional transport equation that accounts for convection and cooling. The short-timescale variability of the emission is explained by local pair injections in turbulent regions of the inner beam.

Results. For illustration, we apply the model to the case of PKS 2155-304, reproducing a quiescent state of emission with inverse Compton and synchrotron radiation from primary electrons, as well as proton-proton interactions in the jet. The latter also yield an accompanying neutrino flux that could be observed with a new generation km-scale detector in the northern hemisphere such as KM3NeT.