1999/06/09 by D. W. Sciama · 38 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Background radiation #Cosmic ray #Dark Matter and Cosmic Phenomena #Dark matter #Flux (metallurgy) #Galactic plane #Galaxies: Formation, Evolution, Phenomena #Galaxy #Milky Way #Molecular cloud #Nuclear physics #Physics #Radiation #Stars #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2000.03072.x
published in Monthly Notices of the Royal Astronomical Society 312(1), 33-38 (Oxford University Press) · 6 pages TEX files, using mn.tex as macro
arxiv created 1999/06/09 · openalex publication_date 2000/02/11 · openalex created_date 2016/06/24 · arxiv updated 2016/08/30 · openalex updated_date 2026/08/05
We explore some basic observational consequences of assuming that the dark matter in the Milky Way consists mainly of molecular clouds, and that cosmic rays can penetrate these clouds. In a favoured model of the clouds, this penetration would have the following consequences, all of which agree with observation. Cosmic ray nuclei would be fragmented when they enter a cloud, giving them a lifetime in the Galaxy of |1015 s (for relativistic nuclei). Pionic γ-rays emitted by the clouds, after proton—proton (pp) collisions, would have a diffuse flux in the Galactic plane comparable to the flux from known sources for photon energies ≳1 GeV. The heat input into the clouds from cosmic rays would be re-radiated mainly in the far-infrared. The resulting radiation background agrees, in both intensity and spectrum in different directions, with a known excess in the far-infrared background of the galaxy over emission by warm dust.