Modelling the variability of 1ES1218+30.4

TL;DR

This paper models the short-term variability of the blazar 1ES1218+30.4 using a synchrotron-self Compton framework, explaining observed light curves and multiwavelength behavior through numerical solutions of plasma kinetic equations.

Contribution

It introduces a numerical SSC model that accounts for short-term variability in blazar emission by incorporating time-dependent electron injection and acceleration processes.

Findings

Short-term variability explained by changing electron injection levels.

Long-term emission consistent with constant SSC emission.

Model reproduces observed VERITAS light curves and multiwavelength behavior.

Abstract

The blazar 1ES1218+30.4 has been previously detected by the VERITAS and MAGIC telescopes in the very high energies. The new detection of VERITAS from December 2008 to April 2009 proves that 1ES1218+30.4 is not static, but shows short-time variability. We show that the time variability may be explained in the context of a self-consistent synchrotron-self Compton model, while the long time observation do not necessarily require a time-resolved treatment. The kinetic equations for electrons and photons in a plasma blob are solved numerically including Fermi acceleration for electrons as well as synchrotron radiation and Compton scattering. The light curve observed by VERITAS can be reproduced in our model by assuming a changing level of electron injection compared to the constant state of 1ES1218+30.4. The multiwavelength behaviour during an outburst becomes comprehensible by the model. The long time measurements of VERITAS are still explainable via a constant emission in the SSC context, but the short outbursts each require a time-resolved treatment.