We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.

Durham e-Theses
You are in:

Some aspects of the cosmic ray origin problem

Freedman, Immanuel (1985) Some aspects of the cosmic ray origin problem. Doctoral thesis, Durham University.



The central contribution of this thesis is a detailed study of cosmic ray acceleration in collapsing gas clouds. The conditions for cosmic ray enhancement in collapsing rotating magnetised clouds during Galaxy formation, cloud formation and subsequent star formation are assessed. The thesis continues with a critical review of antiproton origin models, together with an assessment of the extra-galactic origin model in terms of the putative Galactic Wind. The thesis finishes with an assessment (and dismissal) of the Galactic Wind terminal shock hypothesis for the origin of the highest energy cosmic rays. The principal conclusion is that the collapse of a gas cloud can yield enhanced cosmic ray flux up to the highest observed enhancement (Carina Nebula). Up to a few percent of Galactic or extragalactic cosmic rays below lO(^15)eV/nucleon may originate this way (a firm upper limit is ~ lO(^21)eV/nucleon). The new model helps to explain the paucity of short pathlengths and somewhat increases the maximum accelerated cosmic ray energy during Supernova shock acceleration of ambient cosmic rays. The model predicts that the luminosity maximum should be from the molecular cloud (not HII region) in the Carina Nebula (for > 100 MeV gamma rays) and that there may be regions of reduced luminosity in the gamma ray sky observable with detectors planned for the future Gamma Ray Observatory.

Item Type:Thesis (Doctoral)
Award:Doctor of Philosophy
Thesis Date:1985
Copyright:Copyright of this thesis is held by the author
Deposited On:15 May 2013 14:13

Social bookmarking: del.icio.usConnoteaBibSonomyCiteULikeFacebookTwitter