TY  - JOUR
A1  - Bykov, Andrei
A1  - Gehrels, Neil
A1  - Krawczynski, Henric
A1  - Lemoine, Martin
A1  - Pelletier, Guy
A1  - Pohl, Martin
T1  - Particle acceleration in relativistic outflows
JF  - Space science reviews
N2  - 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.
KW  - Cosmic rays
KW  - Particle acceleration
KW  - Shocks
Y1  - 2012
U6  - https://doi.org/10.1007/s11214-012-9896-y
SN  - 0038-6308
VL  - 173
IS  - 1-4
SP  - 309
EP  - 339
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Telezhinsky, Igor O.
A1  - Dwarkadas, Vikram V.
A1  - Pohl, Martin
T1  - Particle spectra from acceleration at forward and reverse shocks of young Type Ia Supernova Remnants
JF  - Astroparticle physics
N2  - 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.
KW  - Supernova Remnants
KW  - Cosmic rays
KW  - Cosmic-ray acceleration
KW  - Hydrodynamics
KW  - Forward and reverse shocks
Y1  - 2012
U6  - https://doi.org/10.1016/j.astropartphys.2011.10.001
SN  - 0927-6505
VL  - 35
IS  - 6
SP  - 300
EP  - 311
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Haeffner, Stephanie
A1  - Stegmann, Christian
A1  - Jung-Richardt, Ira
T1  - Systematic search for molecular clouds near supernova remnants as sources of very-high-energy gamma-ray emission
JF  - Astroparticle physics
N2  - Supernova remnants accelerate particles up to energies of at least 100 TeV as established by observations in very-high-energy gamma-ray astronomy. Molecular clouds in their vicinity provide an increased amount of target material for proton-proton interaction and subsequent neutral pion decay into gamma-rays of accelerated hadrons escaping the remnant. Therefore, these molecular clouds are potential gamma-ray sources. The gamma-ray emission from these clouds provides a unique environment to derive information on the propagation of very-high-nergy particles through the interstellar medium as well as on the acceleration of hadrons in supernova remnants. Current Imaging Atmospheric Cherenkov Telescope systems are suitable to explore a large parameter space of the propagation properties depending on the age of the supernova remnant and the distance between the remnant and the nearby molecular cloud.
 In this paper we present our strategy and results of a systematic search for gamma-ray emitting molecular clouds near supernova remnants which are potentially detectable with current experiments in the TeV energy range and explore the prospects of future experiments.
KW  - VHE gamma-ray astronomy
KW  - Supernova remnants
KW  - Molecular clouds
KW  - Cosmic rays
KW  - Galactic Ring Survey
KW  - HESS Galactic Plane Survey
Y1  - 2015
U6  - https://doi.org/10.1016/j.astropartphys.2015.05.004
SN  - 0927-6505
SN  - 1873-2852
VL  - 71
SP  - 36
EP  - 44
PB  - Elsevier
CY  - Amsterdam
ER  -