Galactic Cosmic Rays from SNRs: Shock Acceleration of Gas and Dust
Abstract
We present a quantitative model of galactic cosmic ray (GCR) origin and acceleration, wherein a mixture of interstellar gas and dust is accelerated by a supernova remnant (SNR) blast wave. The gas and dust are accelerated simultaneously, but differences in how each component is treated by the shock leaves a distinctive signature which we believe exists in the cosmic ray data. We abandon the long held assumption that GCR abundances are determined by first ionization potential (FIP). Instead, volatility and mass (presumably mass-to-charge ratio) seem to better organize the data: among the volatile elements, the abundance enhancements relative to solar increase with mass; the refractory elements seem systematically overabundant relative to the more volatile ones in a quasi-mass-independent fashion. We present results from a nonlinear shock model which includes the acceleration of gas-phase ions, the acceleration of weakly charged grains to ~ 100 keV/amu energies, frictional energy losses of grains, the sputtering of grains, and the simultaneous acceleration of the sputtered ions to TeV energies. The model produces GCR abundances and spectra consistent with observations.
- Publication:
-
APS April Meeting Abstracts
- Pub Date:
- April 1997
- Bibcode:
- 1997APS..APR.M1202E