We give a review of cosmic ray propagation models. It is shown that the development of the theory of cosmic ray origin leads inevitably to the conclusion that cosmic ray propagation in the Galaxy is determined by effective particle scattering, which is described by spatial diffusion. The Galactic Disk is surrounded by an extended halo, in which cosmic rays are confined before escaping into inte...

Short Title: Cosmic-ray electrons and diffuse gamma-ray spectrum 1 Abstract The bulk of the diffuse galactic gamma-ray emission above a few tens of GeV has been conventionally ascribed to the decay of neutral pions produced in cosmic-ray interactions with interstellar matter. Cosmic-ray electrons may, however, make a significant contribution to the gamma-ray spectrum at high energies, and even ...

We show that the luminosity of a star forming galaxy is capped by the production and subsequent expulsion of cosmic rays from its interstellar medium. By defining an Eddington luminosity in cosmic rays, we show that the star formation rate of a given galaxy is limited by its mass content and the cosmic ray mean free path. When the cosmic ray luminosity and pressure reaches a critical value as a...

Confinement of cosmic rays by turbulent magnetic fields and the relation between magnetic and cosmic ray energy densities are investigated. Cosmic rays are assumed to diffuse preferentially along magnetic field lines. The implementation into a nonconservative high-order finite difference code is discussed. By solving an explicitly time-dependent equation for the cosmic ray energy flux, causalit...

[1] The indirect radiative forcing of atmospheric aerosols is sensitive to particle size and concentration, which are influenced significantly by nucleation processes. Via its role in aerosol formation, cosmic ray may affect the cloud condensation nuclei abundance and hence the global cloud properties and climate. Systematic variations in ionization rates due to the modulation of cosmic ray rad...

The Perseus galaxy cluster was observed by the MAGIC Cherenkov telescope for a total effective time of 24.4 hours during November and December 2008. No significant γ-ray excess was detected. The resulting upper limits on the γ-ray emission above 100 GeV are 4.63 and 6.55 × 10−12cm−2 s−1 for spectral indices of −1.5 and −2.2, respectively. The obtained limits constrain the emission produced by c...

We review the evidence for cosmic ray acceleration in the superbubble/hot phase of the interstellar medium, and discuss the implications for the composition of cosmic rays and the structure and evolution of the interstellar medium (ISM). We show that the bulk of the galactic supernovae, their expanding remnants, together with their metal-rich grain and gas ejecta, and their cosmic ray accelerat...

A fixed-point measurement of cosmic-ray intensity has being continued at Chiba, near Tokyo in Japan to obtain the time-sequential data. High efficiency neutron rem counter and Multi-sphere neutron Spectrometer (Bonner Sphere: BS) were used for the measurement of cosmic-ray neutron components and for the evaluation of the cosmic-ray ionizing components, NaI(Tl) scintillation spectrometer was emp...

The total cosmic-ray luminosity of the Galaxy is an important constraint on models of cosmic-ray generation. The diffuse high energy γ-ray and radio-synchrotron emissions of the Milky Way are used to derive this luminosity. The result is almost two orders of magnitude larger than the standard estimate, based on the observed isotopic abundances of cosmic ray nuclides. We discuss the plausible in...

We show that recent γ-ray observations of the Small Magellanic Cloud with EGRET rule out a universal cosmic ray flux only at energies below ≈ 10 GeV, while the observed diffuse X-ray and γ-ray background radiations have already ruled out, by more than three orders of magnitude, a universal extragalactic cosmic ray flux identical to that observed in the local solar neighborhood at energies below...