Bottom-up modelling of gamma-ray blazars

Abstract

I discuss blazar modelling from the point of view of the radiating particles and emphasise the role of low-energy emission in high-energy variability studies. I address problems that can arise from focusing on the high-energy spectrum and variability without taking into account the low-frequency behaviour and data - especially if the low-frequency emission is the most direct signature of the particles producing the gamma flares (shock-in-jet models). I use recent Planck observations combined with long-term monitoring of AGNs as examples and for motivation for the "bottom-up" direction - starting from the particles and the low-energy emission - in modelling gamma-ray blazars.