Particle Acceleration in Supernova Remnants and the Resulting Nonthermal Emission

We give an overview on the theoretical description of individual supernova remnants (SNRs) as particle accelerators and report about the latest developments regarding Tycho’s SN, SN 1006, Cassiopeia A, and especially SNR RXJ1713.7-3946. In all these objects the nuclear relativistic component dominates over the relativistic electron component. Then we discuss the global nonthermal effects of SNRs. The entire population of SNRs in our Galaxy collectively drives a Galactic Wind that extends halfway to the neighboring galaxies, the CRs being dynamically important. The same is probably true for the diffuse intergalactic medium around field galaxies, especially starburst galaxies. The intracluster medium in galaxy clusters contains a significant nonthermal energy fraction, more or less in equal share the result of star formation, AGN activity and cluster accretion. It should be observable in high energy gamma rays. To wherever the nonthermal component extends, it is expected to be in rough equipartition with the thermal gas. This “Nonthermal Universe” is the result of cosmic structure formation