2008/11/30 by J. Tammi, Joni Tammi, Peter Duffy · 2 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Gamma-ray bursts and supernovae #Radio Astronomy Observations and Technology #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.14270.x
7 pages, 5 figures, accepted for publication in the MNRAS. v2: Updated the references
arxiv created 2008/12/01 · openalex publication_date 2009/01/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Observations of minute-scale flares in TeV Blazars place constraints on particle-acceleration mechanisms in those objects. The implications for a variety of radiation mechanisms have been addressed in the literature; in this paper, we compare four different acceleration mechanisms: diffusive shock acceleration, second-order Fermi, shear acceleration and the converter mechanism. When the acceleration time-scales and radiative losses are taken into account, we can exclude shear acceleration and the neutron-based converted mechanism as possible acceleration processes in these systems. The first-order Fermi process and the converter mechanism working via synchrotron self-Compton (SSC) photons are still practically instantaneous, however, provided sufficient turbulence is generated on the time-scale of seconds. We propose stochastic acceleration as a promising candidate for the energy-dependent time delays in recent gamma-ray flares of Markarian 501.