Speaker
Description
Observations have established supernova remnants (SNRs) as efficient accelerators of cosmic rays, in particular electrons. Whereas the acceleration process is known in principle, many aspects are poorly understood. In fact, a number of central points that were considered certain twenty years ago have since had to be discarded. It is still unclear how the soft production spectrum required by the observed spectrum of cosmic rays can be achieved or whether SNRs are able to accelerate protons to the ‘knee’ at about 3 PeV.
Most SNRs are created in core-collapse explosions and expand into the wind bubble of their progenitor stars. This circumstellar medium (CSM) features a complex spatial distribution of gas and magnetic field that strongly affects and modifies key ingredients for particle acceleration, such as particle injection and confinement, shock conditions, and acceleration efficiency. In this talk we specifically discuss the prospects for reaching the PeV scale and spectral variations between various elements that derive from abundance gradients in the circumstellar medium.
