Starbursts & Supernovae: Nature’s High Energy Particle Accelerator?

Jay Gallagher, Department of Astronomy, UW-Madison

The Milky Way is permeated by high-energy hadronic and leptonic cosmic rays that connect to interstellar magnetic fields and interact with interstellar gas. Although shocks in remnants of supernovae can accelerate electrons and nuclei to PeV energies, the sources of higher energy cosmic rays remain to be understood. The advent of multi-messenger astronomy has opened a new window on the century old problem of cosmic ray origins, beginning with radio observations and extending to the detection of gamma-rays and neutrinos from cosmic sources.

In this talk I will present results from a study of cosmic ray interactions in starburst galaxies, which represent a first step towards understanding the characteristics of nature’s cosmic particle accelerators.