Cosmic Rays (CR) travel at speeds essentially indistinguishable from the speed of light. However whilst travelling through magnetic fields, both regular and turbulent, they are delayed behind the light since they are usually charged particles and their paths are not linear. Those delays can be so long that they are an impediment to correctly identifying sources which may be variable in time. Fu...

cosmic rays (cr) travel at speeds essentially indistinguishable from the speed of light. however whilst travelling through magnetic fields, both regular and turbulent, they are delayed behind the light since they are usually charged particles and their paths are not linear. those delays can be so long that they are an impediment to correctly identifying sources which may be variable in time. fu...

Abstract: The long-duration balloon flights of TRACER provide new measurements of the intensities and energy spectra of the arriving cosmic-ray nuclei with 5 ≤ Z ≤ 26 at high energies. In order to determine the particle composition and energy spectra at the cosmic-ray sources, changes occurring during the interstellar propagation of cosmic rays must be known. We use a simple propagation model w...

This work presents preliminary results for the time-dependent cosmic-ray propagation in the Galaxy by a fully 3-dimensional Monte Carlo simulation. The distribution of cosmic-rays (both protons and helium nuclei) in the Galaxy is studied on various spatial scales for both constant and variable cosmicray sources. The continuous diffuse gamma-ray emission produced by cosmic-rays during the propag...

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...

The energy spectrum of cosmic-ray antiprotons ( &pmacr;'s) has been measured in the range 0.18-3.56 GeV, based on 458 &pmacr;'s collected by BESS in a recent solar-minimum period. We have detected for the first time a characteristic peak at 2 GeV of &pmacr;'s originating from cosmic-ray interactions with the interstellar gas. The peak spectrum is reproduced by theoretical calculations, implying...

We briefly describe the energy loss processes of ultrahigh energy protons, heavier nuclei and gamma rays in interactions with the universal photon fields of the Universe. We then discuss the modification of the accelerated cosmic ray energy spectrum in propagation by the energy loss processes and the charged cosmic ray scattering in the extragalactic magnetic fields. The energy lost by the ultr...

We have developed a model which aims to reproduce observational data of many kinds related to cosmic-ray origin and propagation: direct measurements of nuclei, antiprotons, electrons and positrons, γ-rays, and synchrotron radiation. Our main results include evaluation of diffusion/convection and reacceleration models, estimates of the halo size, calculations of the interstellar positron and ant...