Letter to the Editor

On the rapid TeV flaring activity of Markarian 501

Department of Physics, University of Athens, Panepistimiopolis, GR 15783 Zografos, Greece e-mail: amastich@phys.uoa.gr

Received: 2 July 2008
Accepted: 11 October 2008

Abstract

Aims. We investigate the one-zone SSC model of TeV blazars in the presence of electron acceleration. In this picture, electrons achieve their maximum energy as the acceleration saturates due to a combination of synchrotron and inverse Compton scattering losses.

Methods. We solve the spatially averaged kinetic equations that describe the simultaneous evolution of particles and photons, obtaining the multiwavelength spectrum as a function of time.

Results. We apply the model to the rapid flare of Mrk 501 of July 9, 2005 as observed by the MAGIC telescope, and derive the relevant parameters for the pre-flare quasi-steady-state and the states during the flare. We demonstrate that a hard lag flare can be obtained with parameters well inside the range expected for this source. In particular, a high value of Doppler factor appears necessary.