Tracing the sources of cosmic rays with molecular ions

Abstract

The rate of ionization by cosmic rays (CRs) in interstellar gas directly associated with γ-ray-emitting supernova remnants (SNRs) is for the first time calculated to be several orders of magnitude larger than the Galactic average. Analysis of ionization-induced chemistry yields the first quantitative prediction of the astrophysical H+2 emission line spectrum, which should be detectable together with H+3 lines. The predicted coincident observation of those emission lines and γ-rays will help prove that SNRs are sources of CRs. © 2011. The American Astronomical Society. All rights reserved.