Year: 2020
Type: article
Abstract: ABSTRACT We calculate spectra of escaping cosmic rays (CRs) accelerated at shocks produced by expanding Galactic superbubbles powered by multiple supernovae producing a continuous energy outflow in star-forming galaxies. We solve the generalized Kompaneets’ equations adapted to expansion in various external density profiles, including exponential and power-law shapes, and take into account that escaping CRs are dominated by those around their maximum energies. We find that the escaping CR spectrum largely depends on the specific density profiles and power source properties, and the results are compared to and constrained by the observed CR spectrum. As a generic demonstration, we apply the scheme to a superbubble occurring in the centre of the Milky Way, and find that under specific parameter sets the CRs produced in our model can explain the observed CR flux and spectrum around the second knee at 1017 eV.
Authors: Zhaowei Zhang, Kohta Murase, Peter Mészáros
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: Collaborative Research: WoU-MMA: Revealing the Fate of Heavy Nuclei in Stellar Explosions and Pathways to Cosmic Rays, Toward Solving Cosmic Particle Mysteries with Neutrinos and Gamma Rays, GAMMA RAY BURSTS (GRB) ARE AMONG THE MOST EXTREME AND EXCITING OBJECTS IN ASTROPHYSICS. MAJOR ADVANCES IN OUR UNDERSTANDING OF THESE SOURCES IN THE L
OpenAlex ID: W3000362625