@article{TelezhinskyDwarkadasPohl2012, author = {Telezhinsky, Igor O. and Dwarkadas, Vikram V. and Pohl, Martin}, title = {Particle spectra from acceleration at forward and reverse shocks of young Type Ia Supernova Remnants}, series = {Astroparticle physics}, volume = {35}, journal = {Astroparticle physics}, number = {6}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0927-6505}, doi = {10.1016/j.astropartphys.2011.10.001}, pages = {300 -- 311}, year = {2012}, abstract = {We study cosmic-ray acceleration in young Type Ia Supernova Remnants (SNRs) by means of test-particle diffusive shock acceleration theory and 1-D hydrodynamical simulations of their evolution. In addition to acceleration at the forward shock, we explore the particle acceleration at the reverse shock in the presence of a possible substantial magnetic field, and consequently the impact of this acceleration on the particle spectra in the remnant. We investigate the time evolution of the spectra for various time-dependent profiles of the magnetic field in the shocked region of the remnant. We test a possible influence on particle spectra of the Alfvenic drift of scattering centers in the precursor regions of the shocks. In addition, we study the radiation spectra and morphology in a broad band from radio to gamma-rays. It is demonstrated that the reverse shock contribution to the cosmic-ray particle population of young Type la SNRs may be significant, modifying the spatial distribution of particles and noticeably affecting the volume-integrated particle spectra in young SNRs. In particular spectral structures may arise in test-particle calculations that are often discussed as signatures of non-linear cosmic-ray modification of shocks. Therefore, the spectrum and morphology of emission, and their time evolution, differ from pure forward-shock solutions.}, language = {en} } @misc{BykovGehrelsKrawczynskietal.2012, author = {Bykov, Andrei and Gehrels, Neil and Krawczynski, Henric and Lemoine, Martin and Pelletier, Guy and Pohl, Martin}, title = {Particle acceleration in relativistic outflows}, series = {Space science reviews}, volume = {173}, journal = {Space science reviews}, number = {1-4}, publisher = {Springer}, address = {Dordrecht}, issn = {0038-6308}, doi = {10.1007/s11214-012-9896-y}, pages = {309 -- 339}, year = {2012}, abstract = {In this review we confront the current theoretical understanding of particle acceleration at relativistic outflows with recent observational results on various source classes thought to involve such outflows, e.g. gamma-ray bursts, active galactic nuclei, and pulsar wind nebulae. We highlight the possible contributions of these sources to ultra-high-energy cosmic rays.}, language = {en} }