Electron acceleration and time variability of high-energy emission from blazars

Blazars are known to emit a broadband emission from radio to gamma rays with rapid time variations, particularly in X-rays and gamma rays. Synchrotron radiation and inverse Compton scattering are thought to play an important role in emission, and the time variations are likely related to the acceleration of nonthermal electrons. As simultaneous multiwavelength observations with continuous time spans have been recently available, some characteristics of electron acceleration can possibly be inferred from the spectral changes of high-energy emission. In order to make such inferences, we solve the time-dependent kinetic equations of electrons and photons simultaneously, using a simple model for electron acceleration. We then show how the time variations of emission are dependent on electron acceleration. We also present a simple model for a flare in X-rays and TeV gamma rays by temporarily changing the acceleration timescale. Our model can be used to analyze observed data in detail to obtain information on electron acceleration in blazars.