Vladimir S. Ptuskin
IZMIRAN, Russia
Acceleration of cosmic rays in magnetic circumstellar bubbles
We consider the diffusive shock acceleration in interstellar bubbles created by powerful stellar winds of supernova progenitors. Under the moderate stellar wind magnetization, the bubbles are filled by the strongly magnetized low-density gas. It is shown that the maximum energy of particles accelerated by a supernova shock moving across the azimuthal magnetic field in this environment can exceed the "knee" in the cosmic ray energy spectrum observed at ~ 3 x 1015 eV. The relevant cosmic-ray and gamma-ray data are discussed. \N