We show that the expected composition of cosmic rays accelerated from the erosion products of fast supernova grains in the hot interstellar medium (HISM) of ejecta enriched superbubbles, where the bulk ( 85%) of Galactic supernovae occur, is consistent with the currently available cosmic ray data. In particular, we show that if the cosmic ray metals come from the sputtering of fast refractory g...

Centaurus A, the cosmic ray accelerator a few Mpc away from us is possibly one of the nearest sources of extremely high energy cosmic rays. We investigate whether the gamma ray data currently available from Centaurus A in the GeV-TeV energy band can be explained with only proton proton interactions. We show that for a single power law proton spectrum, mechanisms of γ-ray production other than p...

Centaurus A, the cosmic ray accelerator a few Mpc away from us is possibly one of the nearest sources of extremely high energy cosmic rays. We investigate whether the gamma ray data currently available from Centaurus A in the GeV-TeV energy band can be explained with only proton proton interactions. We show that for a single power law proton spectrum, mechanisms of γ-ray production other than p...

Detecting gamma-rays from discrete astronomical objects offers the potential to directly study sites of cosmic particle acceleration. Alternatively, the pervasive diffuse gamma-ray emission component caused by interactions of cosmic rays with interstellar gas and radiation fields carries information about the spatial distribution of cosmic particle accelerators and reveals details about the cha...

EGRET data on the Gamma ray emission from the inner Galaxy have shown a rather flat spectrum. This spectrum extends to about 50 GeV in photon energy. It is usually assumed that these gamma-rays arise from the interactions of cosmic ray nuclei with ambient matter. Cosmic Ray particles have been observed up to 3 10 20 eV, with many arguments suggesting, that up to about 3 10 18 eV they are of Gal...

Diffuse interstellar clouds show large abundances of H3 which can be maintained only by a high ionization rate of H2. Cosmic rays are the dominant ionization mechanism in this environment, so the large ionization rate implies a high cosmic-ray flux, and a large amount of energy residing in cosmic rays. In this paper we find that the standard propagated cosmic-ray spectrum predicts an ionization...

We report high-resolution observations made in interplanetary space of 83-284 MeV per nucleon galactic cosmic-ray iron isotopes and directly establish that 56Fe is the dominant cosmic-ray Fe isotope. We find the following percentage abundances for Fe at the cosmic-ray source: 54Fe = 9(+8, -5)%, 55Fe:::; 7%, 56Fe = 91(+5, -11)%, 57Fe:::; 8%, and 58Fe:::; 6%. When compared to calculated nucleosyn...

Contribution of nearby pulsars to the cosmic rays observed at Earth has been studied. It is found that the experimental bound on amplitude of cosmic ray anisotropy may produce significant constraint on the efficiency of converting pulsar rotational energy to emitted particles kinetic energy. Cosmic ray fluxes from two well known nearby gamma ray pulsars, namely the Vela and Geminga pulsars, are...

EGRET data on the Gamma ray emission from the inner Galaxy have shown a rather flat spectrum. This spectrum extends to about 50 GeV in photon energy. It is usually assumed that these gamma-rays arise from the interactions of cosmic ray nuclei with ambient matter. Cosmic Ray particles have been observed up to 3 10 20 eV, with many arguments suggesting, that up to about 3 10 18 eV they are of Gal...