33RD INTERNATIONAL COSMIC RAY CONFERENCE, RIO DE JANEIRO 2013 THE ASTROPARTICLE PHYSICS CONFERENCE Blazar SEDs

Abstract: Blazars are among the most violent sources in the cosmos exhibiting flaring states with remarkably different variability time scales. Especially rapid flares with flux doubling time scales of the order of minutes have been puzzling for quite some time. Many modeling attempts use the well known linear relations for the cooling and emission processes in the jet in a steady-state scenario, albeit the obvious strongly time-dependent nature of flares. Due to the feedback of the self-produced synchrotron radiation with additional scattering by the relativistic electrons, the synchrotron-self Compton (SSC) effect is inherently time-dependent. Recently, in an ongoing series of papers an analytical analysis on the effects of this nonlinear behavior has been presented. Here, we report the results concerning the effect of the time-dependent SSC cooling on the spectral energy distribution (SED), and the synchrotron lightcurves of blazars. For that, we calculated analytically the synchrotron, SSC and external Compton (EC) component of the SED, giving remarkably different spectral features compared to the standard linear approach. We were able to show that the resulting fluxes strongly depend on the parameters, and that SSC could potentially have a strong effect even in sources with strong external photon fields (such as FSRQs), contrary to what is usually assumed. For the synchrotron lightcurve we considered the effects of retardation, including the geometry of the source. The retardation might wash out some effects of the time-dependent cooling, but since lightcurves and SEDs have to be fitted simultaneously with the same set of parameters, the results giv