Oral Presentation

Stochastic Acceleration for Hard Electron Spectra of Blazars

Author(s): Jun Kakuwa

Presenter: Jun Kakuwa (Hiroshima University)

Nonthermal emissions of blazars suggest the existence of nonthermal electrons in subparsec scale jets of AGNs, although the production process of the high-energy electrons has not yet been clarified. Basically, electron acceleration mechanisms at shocks and those in turbulent fields have been considered (e.g., Kakuwa et al. 2015, MNRAS) as in the case of larger scale jets. For a decade, the latter mechanisms have been discussed to interpret hard photon spectra of blazars such as 1ES 1101-232 and 1ES 0229+200. However, the damping effect of the turbulent fields due to the acceleration has not been taken into account in the discussions so far. Here, we demonstrate a case in which a softer electron distribution than expected is formed, considering the cascading Alfven wave turbulence and its damping due to the gyroresonant interaction (Kakuwa 2016, ApJ). The inclusion of the damping might be generally (not only for blazars) important in understanding the role of high-energy particles in a turbulent boundary layer of the jets.