Cosmic Rays, Supernova, and the Origin of Ultrahigh Energy Particles
Author | : |
Publisher | : |
Total Pages | : |
Release | : 1985 |
ISBN-10 | : OCLC:727272055 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
Download or read book Cosmic Rays, Supernova, and the Origin of Ultrahigh Energy Particles written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The acceleration of ultrahigh energy cosmic rays, greater than or equal to10/sup 15 -20/ eV, is still an unsolved problem in high-energy astrophysics. The now classical mechanism of stochastic acceleration of cosmic rays in a strong shock in the interstellar or intergalactic medium is limited in time and dimension for all likely acceleration sites, particularly for the highest energies. Acceleration of cosmic rays across a plasma shock of velocity, .beta./sub s/ (.beta./sub s/ = v/sub shock//c), requires 1/.beta./sub s/ number of crossings and therefore (1/.beta./sub s/)2 number of scatterings for doubling the energy of a particle. This requires a space of the order of 1/.beta./sub s/ x the scattering length, or a multiple of the Larmor radius and hence, the space requirements to cosmic ray acceleration are very many Larmor orbits in dimension, as well as times that are larger by (1/.beta./sub s/)2 x t/sub Larmor/. The acceleration of cosmic rays by the shock in the envelope of a Type 1 supernova is reviewed, and the interaction of the accelerated matter with the nearby ISM is considered. The spectrum of relativistic ejected matter is preferentially trapped in the ISM. Further acceleration of each energy group should take place in both the near relativistic shock wave and the compression by the following matter. The possible acceleration of ultrahigh energy cosmic rays in the accretion disk of a near-stationery magnetic neutron star such as Cyg-X3 is another strong possibility. Here the diffusion of magnetic flux radially outwards opposite to the viscous diffusion of mass radially inwards is considered as a likely topology for a unipolar generator acceleration of ultrahigh energy particles.