Cosmic-Ray-Induced Ionization in Molecular Clouds Adjacent to Supernova Remnants
Paper i proceeding, 2013

Energetic gamma rays (GeV to TeV photon energy) have been detected toward several supernova remnants (SNR) that are associated with molecular clouds. If the gamma rays are produced mainly by hadronic processes rather than leptonic processes like bremsstrahlung, then the flux of energetic cosmic ray nuclei (>1GeV) required to produce the gamma rays can be inferred at the site where the particles are accelerated in SNR shocks. It is of great interest to understand the acceleration of the cosmic rays of lower energy (<1GeV) that accompany the energetic component. These particles of lower energy are most effective in ionizing interstellar gas, which leaves an observable imprint on the interstellar ion chemistry. A correlation of energetic gamma radiation with enhanced interstellar ionization can thus be used to support the hadronic origin of the gamma rays and to constrain the acceleration of ionizing cosmic rays in SNR. Using observational gamma ray data, the primary cosmic ray proton spectrum can be modeled for E>1GeV, and careful extrapolation of the spectrum to lower energies offers a method to calculate the ionization rate of the molecular cloud.

cosmic rays

gamma rays

molecular clouds


F. Schuppan

Ruhr-Universität Bochum

Julia K. Becker

Ruhr-Universität Bochum

John H Black

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

S. Casanova

North-West University

M. Mandelartz

Ruhr-Universität Bochum

Astrophysics and Space Science Proceedings

15706591 (ISSN) 15706605 (eISSN)

Vol. 34 317-324
978-364235409-0 (ISBN)

2nd Workshop on cosmic-ray induced phenomenology in star-forming environments, 2012
Catalonia, Spain,


Astronomi, astrofysik och kosmologi


Grundläggande vetenskaper


Onsala rymdobservatorium



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