Dresden 2013 – scientific programme

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T: Fachverband Teilchenphysik

T 84: Gammaastronomie 4

T 84.2: Talk

Wednesday, March 6, 2013, 17:00–17:15, HSZ-E05

Tracing the origin of cosmic rays from SNRs in molecular clouds — •Florian Schuppan¹, Julia Tjus¹, and John H. Black² — ¹Ruhr-Universität Bochum, Fakultät für Physik & Astronomie, Theoretische Physik I, 44780 Bochum, Germany — ²Dept. of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden

Observed by a variety of instruments, supernova remnants are known to be sources of cosmic rays. As a consequence, they are often bright in gamma rays. However, whether the gamma rays are caused by electrons or high energy protons –neither of them directly observable– is very difficult to tell from gamma detections only. A correlation study might help distinguishing a leptonic scenario from a hadronic one for supernova remnants interacting with a molecular cloud. If there is a molecular cloud in the vicinity of a supernova remnant, the cosmic rays interact with cloud matter. Low energy protons accelerated by the supernova remnant are very efficient in ionizing the cloud, whereas electrons do penetrate the cloud sufficiently deep to significantly contribute to the total ionization rate. Therefore, if prominent ionization features are observed in spatial correlation with gamma rays towards the molecular cloud, this would be a hint at hadronic origin of the gamma rays. Profiles of the ionization rate as a function of penetration depth into the cloud from cosmic ray protons and X-rays are calculated to examine the possibility of detectable ionization features from cosmic rays to unambiguously check a hadronic origin of the gamma rays.