Models for High-Energy Radiation from Blazars

We discuss on the modelling of blazar jets as emitters of multiwavelength radiation with the implementation of a lepto-hadronic treatment. Assuming that injection of non-thermal electrons and protons can take place at the base of the jet, the stationary particle distributions can be found using an inhomogeneous one-dimensional transport equation with cooling and convection. The goal of this approach is to replace the widely used one-zone purely leptonic approximation by a more realistic model. We argue that the rapid variability observed in emission from blazars can be obtained as a result of interaction of the jet with obstacles, i.e., molecular clouds and stars. Long term variability is likely related to changes in the injection and physical conditions in the acceleration region.