Related papers: Cosmic rays and changes in atmospheric infra-red t…
Interpretations of synchrotron observations often assume a tight correlation between magnetic and cosmic ray energy densities. We examine this assumption using both test-particle simulations of cosmic rays and MHD simulations which include…
Cosmic rays represent one of the most important energy transformation processes of the universe. They bring information about the surrounding universe, our galaxy, and very probably also the extragalactic space, at least at the highest…
We argue that the asymmetry between diverging and converging electromagnetic waves is just one of many asymmetries in observed phenomena that can be explained by a past hypothesis and statistical postulate (together assigning probabilities…
We consider the modification of extragalactic cosmic ray spectrum caused by cosmic ray interactions with infrared background photons which are present in the extragalactic space together with relic photons. It is assumed that cosmic ray…
A decrease in the globally averaged low level cloud cover, deduced from the ISCCP infra red data, as the cosmic ray intensity decreased during the solar cycle 22 was observed by two groups. The groups went on to hypothesise that the…
The origin of Galactic cosmic-ray ions has remained an enigma for almost a century. Although it has generally been thought that they are accelerated in the shock waves associated with powerful supernova explosions-for which there have been…
The dependence of the cosmic ray intensity on Galactocentric distance is known to be much less rapid than that to be thought-to-be sources: supernova remnants. This is an old problem ('the radial gradient problem') which has led to a number…
Substantial amount of information both on the source and on characteristics of intercepting magnetic fields is encoded in the distribution in arrival times, directions, and energies of charged ultra-high energy cosmic rays from discrete…
Cosmic rays are an essential ingredient in the evolution of the interstellar medium, as they dominate the ionisation of the dense molecular gas, where stars and planets form. However, since they are efficiently scattered by the galactic…
Observations of line ratios in the Milky Way's warm ionized medium (WIM) suggest that photoionization is not the only heating mechanism present. For the additional heating to explain the discrepancy it would have to have a weaker dependence…
We present a new calculation of the intergalactic $\gamma$-ray pair-production absorption coefficient as a function of both energy and redshift up to the redshift of 3C279, z = 0.54. In reexamining this problem, we make use of new…
In this paper we briefly discuss the problem of the origin of Ultra High Energy Cosmic Rays in the framework of Top-Down models. We show that, for high energy of decays and in a wide range of spectra of injected protons, their extragalactic…
Detailed composition measurements can be a very powerful means of tracing origins, a fact used regularly by forensic scientists and art historians. One of the main motivating factors for making detailed observations of cosmic rays was…
A significant correlation between the annual cosmic ray flux and the amount of low clouds has recently been found for the past 20 years. However, of the physical explanations suggested, none has been quantitatively verified in the…
We investigate the propagation of ultra-high energy cosmic ray nuclei (A = 1-56) from cosmologically distant sources through the cosmic radiation backgrounds. Various models for the injected composition and spectrum and of the cosmic…
Recent results from multi-wavelength observations of the inner few hundred pc of the Galactic center have added two new characteristics to the ISM in this unique region. One is the cosmic ray ionization rate derived from H$_3^+$…
We present a new calculation of the intergalactic gamma-ray absorption coefficient as a function of both energy and redshift. In reexamining this problem, we make use of a new, empirically based calculation (as opposed to previous model…
Cosmic-rays constitute the main ionising and heating agent in dense, starless, molecular cloud cores. We reexamine the physical quantities necessary to determine the cosmic-ray ionisation rate (especially the cosmic ray spectrum at E < 1…
The Galactic cosmic ray (GCR) intensity has been postulated by others to vary cyclically with a peak to valley ratio of ~3:1, as the Solar System moves from the Spiral Arm to the Inter-Arm regions of the Galaxy. These intensities have been…
I review here some of the physics we are learning and expect to learn in the near future through the observation of cosmic rays. The study of cosmic rays involves a combination of data from accelerators, ground arrays, atmospheric…