2013/11/01 by Boaz Katz, Katz, Boaz, Eli Waxman +6
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE) #astro-ph.HE
paper · pdf · doi:10.48550/arxiv.1311.0287
5 pages, 1 figure
arxiv created 2013/11/01 · openalex publication_date 2013/11/01 · arxiv updated 2013/11/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The energy output (per logarithmic interval of particle energies) of Cosmic Rays (CRs) with energies 10\rm GeV\lesssimεp\lesssim100\rm GeV is ∼ 1047\rm erg per solar mass of star-formation, based on the CR production rate in the Milky Way and in starburst galaxies, implying a generation rate of εp2Q∼ 1045\rm erg~Mpc-3~yr-1 in the local universe. It is only ∼ 10 times larger than the output, εp2 Q=0.5±0.2× 1044\rm erg~Mpc-3~yr-1, of Ultra High Energy CRs (UHECRs) at energies 1010.5\rm GeV<εp<1012\rm GeV (obtained assuming they are mostly protons), which in turn is comparable to the lower limit of εp2 Q≥ 0.5× 1044\rm erg~Mpc-3~yr-1 of high energy CRs with 106\rm GeV\lesssimεp\lesssim 108\rm GeV implied by the saturation of the Waxman-Bahcall bound by the neutrino excess recently discovered by IceCube. These similarities are consistent with a flat production spectrum, εp2 Q∼ const for CRs at all observed energies. If a flat production spectrum is generated by our galaxy, the observed CR flux in the range 106.5-109.5\rm GeV, above the "knee", is suppressed compared to lower energies due to propagation effects rather than acceleration upper limits. As suggested by Parizot and Aublin, the most exciting possibility is that cosmic rays at all energies are emitted from a single type of (unknown) sources, which can not be supernova remnants.