A&A 465, 695-702 (2007)
DOI: 10.1051/0004-6361:20066494
Analytical solutions for energy spectra of electrons accelerated by nonrelativistic shock-waves in shell type supernova remnants
V. N. Zirakashvili1, 2 and F. Aharonian2, 31 Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation, 142190 Troitsk, Moscow Region, Russia
e-mail: zirak@izmiran.ru
2 Max-Planck-Institut für Kernphysik, Postfach 103980, 69029 Heidelberg, Germany
3 Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin 2, Ireland
(Received 2 October 2006 / Accepted 12 January 2007)
Abstract
Context.Recent observations of hard X-rays and very high energy gamma-rays
from a number of young shell type supernova remnants indicate
the importance of detailed quantitative studies of energy spectra of relativistic
electrons formed via diffusive shock acceleration
accompanied by intense nonthermal emission through
synchrotron radiation and inverse Compton scattering.
Aims.The aim of this work was derivation of exact asymptotic
solutions of the kinetic equation which describes the energy
distribution of shock-accelerated electrons
for an arbitrary energy-dependence of the diffusion coefficient.
Methods.The asymptotic solutions at low and very high energy domains coupled
with numerical calculations in the intermediate energy range allow
analytical presentations of energy spectra of electrons for
the entire energy region.
Results.Under the assumption that the energy losses of electrons are
dominated by synchrotron cooling, we derived the exact asymptotic
spectra of electrons without any restriction on the
diffusion coefficient. We also obtained
simple analytical approximations which describe,
with accuracy better than ten percent, the energy spectra of
nonthermal emission of shock-accelerated electrons due to
the synchrotron radiation and inverse Compton scattering.
Conclusions.The results can be applied for interpretation of
X-ray and gamma-ray observations of shell type supernova remnants,
as well as other nonthermal high energy source populations
like microquasars and large scale synchrotron jets of
active galactic nuclei.
Key words: acceleration of particles -- radiation mechanism: non-thermal -- shock waves -- ISM: supernova remnants
© ESO 2007

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