EDP Sciences
Free access
Volume 423, Number 1, August III 2004
Page(s) 13 - 19
Section Astrophysical processes
DOI http://dx.doi.org/10.1051/0004-6361:20047065

A&A 423, 13-19 (2004)
DOI: 10.1051/0004-6361:20047065

Radio emission and particle acceleration in plerionic supernova remnants

C. Nodes, G. T. Birk, M. Gritschneder and H. Lesch

Institute for Astronomy and Astrophysics, University of Munich, Germany
    e-mail: nodes@usm.uni-muenchen.de

(Received 13 January 2004 / Accepted 7 May 2004)

Plerionic supernova remnants exhibit radio emission with remarkably flat spectral indices ranging from $\alpha=0.0$ to $\alpha=-0.3$. The origin of very hard particle energy distributions still awaits an explanation, since shock waves generate particle distributions with synchrotron spectra characterized by $\alpha\le-0.5$. Acceleration of high energy leptons in magnetohydrodynamic turbulence instead may be responsible for the observed hard spectra. This process is studied by means of relativistic test particle calculations using electromagnetic fields produced by three-dimensional simulations of resistive magnetohydrodynamical turbulence. The particles receive power-law energy spectra $N(\gamma)\propto \gamma^{-s}$ with  s ranging from  1.2 to  1.6, i.e. particle spectra that are required to explain the radio emission of plerions.

Key words: stars: pulsars: individual: Crab -- radio continuum: stars -- acceleration of particles -- turbulence

© ESO 2004