Cosmic Ray Origin and Propagation Model

TL;DR

This paper models the Galactic origin and propagation of cosmic rays, emphasizing supernova shock acceleration, diffusive losses, and spallation, while analyzing particle injection states and contributions from massive stars.

Contribution

It demonstrates that particles are injected as one or two times ionized and quantifies the contribution of massive stars to cosmic rays, also examining injection conditions.

Findings

Particles are injected as one or two times ionized.

Massive stars contribute a 1:2 ratio for elements with Z≥6.

Injection velocities, energies, or momenta are analyzed.

Abstract

It is presumed that the observed cosmic rays up to about $3\times 10^{18}$ eV are of Galactic origin, the particles being the ones which are found in the composition of the stellar winds of stars that explode as supernova into the interstellar medium (ISM) or into their winds. These particles are accelerated in the supernova shock. In order to obtain the observed cosmic ray spectrum it is necessary to take into account the diffusive losses in the Galaxy (which are making the energy spectrum more steeper). Another modification of the source spectrum is due to the fragmentation (spallation) of the cosmic ray particles, after their collision with the ISM atoms. In this paper we are proving that some particles are injected in the supernova shock one or two time ionized, and, also, that the contribution of massive stars ($30 M_{\odot}\leq M\leq 50 M_{\odot}$) accelerated particles to cosmic rays (where the winds are highly enriched in heavy elements) is 1:2 for elements with $Z\geq 6$. Another goal of this paper is to check if the particles are injected with the same velocity, energy or momentum.