# Variability studies and modeling of the blazar PKS 2155-304 in the light of a decade of multi-wavelength observations

## TL;DR

This study analyzes a decade of multi-wavelength data on blazar PKS 2155-304, revealing log-normal variability, potential periodicity, and modeling its behavior with a synchrotron self-Compton approach.

## Contribution

It provides a comprehensive variability analysis over ten years and introduces a successful time-dependent model to explain observed behaviors and potential periodicity.

## Key findings

- Optical and X-ray variability follow a log-normal distribution.
- A tentative 700-day periodicity is identified.
- A one-zone synchrotron self-Compton model reproduces variability evolution.

## Abstract

The variability of the high-frequency peaked BL Lac object PKS 2155-304 is studied using almost 10 years of optical, X-ray and gamma-rays data. Publicly available data have been gathered and analyzed with the aim to characterize the variability and to search for log-normality or periodic behavior. The optical and X-ray range follow a log-normal process; a hint for a periodicity of about 700 days is found in optical and in the high energy (100 MeV <E<300 GeV) range. A one zone, time-dependent, synchrotron self-Compton model is successfully used to reproduce the evolution with energy of the variability and the tentatively reported periodicity.