Related papers: Magnetic fields and cosmic rays in clusters of gal…
Clusters of galaxies can potentially produce cosmic rays (CRs) up to very-high energies via large-scale shocks and turbulent acceleration. Due to their unique magnetic-field configuration, CRs with energy $\leq 10^{17}$ eV can be trapped…
Several binary systems consisting of a massive star and a compact object have been detected above 100 GeV in the Galaxy. In most of these sources, gamma-rays show a modulation associated to the orbital motion, which means that the emitter…
In this work, we compute the contribution from clusters of galaxies to the diffuse neutrino background. Clusters of galaxies can potentially produce cosmic rays (CRs) up to very-high energies via large-scale shocks and turbulent…
Many galaxy clusters have giant halos of non-thermal radio emission, indicating the presence of relativistic electrons in the clusters. Relativistic protons may also be accelerated by merger and/or accretion shocks in galaxy clusters. These…
Radio, X-ray and infrared observations of the inner few hundred pc of the Galactic center have highlighted two characteristics to the ISM. The cosmic ray ionization rate derived from molecular ions such as H$^+_3$, is at least two to three…
(Abridged) A model for the escape of CR particles from radio galaxy cocoons is presented here. It is assumed that the radio cocoon is poorly magnetically connected to the environment. An extreme case of this kind is an insulating boundary…
Large-scale diffuse radio emission is observed in some clusters of galaxies. There is ample of evidence that the emission has its origin in synchrotron losses of relativistic electrons, accelerated in the course of clusters mergers. In a…
Equipartition arguments provide an easy way to find a characteristic scale for the magnetic field from radio emission, by assuming the energy densities in cosmic rays and magnetic fields are the same. Yet most of the cosmic ray content in…
We present a detailed examination of the relationship between the magnetic field structures and the variations in Faraday Rotation across PKS1246-410, a radio source in the Centaurus cluster of galaxies, using data from Taylor, Fabian and…
Recently the AGASA Collaboration presented data suggesting a significant clustering of ultra-high energy cosmic rays coming from the outer Galaxy region. In this paper we calculate expected cosmic ray arrival distributions for several…
Observations of diffuse radio emission in galaxy clusters indicate that cosmic-ray electrons are accelerated on $\sim$Mpc scales. However, protons appear to be accelerated less efficiently since their associated hadronic $\gamma$-ray…
It is generally accepted that radio relics are the result of synchrotron emission from shock-accelerated electrons. Current models, however, are still unable to explain several aspects of their formation. In this paper, we focus on three…
There is now firm evidence that the ICM consists of a mixture of hot plasma, magnetic fields and relativistic particles. The most important evidences for non-thermal phenomena in galaxy clusters comes from the diffuse Mpc-scale synchrotron…
There is compelling evidence that at least some clusters of galaxies are powerful sources of non-thermal radiation. In all cases where this radiation has been detected, a general trend is that high energy densities of cosmic rays and…
Because accretion and merger shocks in clusters of galaxies may accelerate particles to high energies, clusters are candidate sites for the origin of ultra-high-energy (UHE) cosmic-rays. A prediction was presented for gamma-ray emission…
Cosmic rays (CRs) interact with the gas, the radiation field and the magnetic field in the Milky Way, producing diffuse emission from radio to gamma rays. Observations of this diffuse emission and comparison with detailed predictions are…
Inspired by the excess soft X-ray emission recently detected in Green Pea galaxies, we model the soft X-ray emission (0.5 - 2.0 keV) of hot gas from star cluster winds. By combining individual star clusters, we estimate the soft X-ray…
The observed bimodality in radio luminosity in galaxy clusters is puzzling. We investigate the possibility that cosmic-ray (CR) streaming in the intra-cluster medium can 'switch off' hadronically induced radio and gamma-ray emission. For…
Accretion of gas onto already virialized structures like galaxy clusters should give rise to accretion shocks which can potentially accelerate cosmic rays. Here, we use the radio emission detected from Coma cluster and models of evolution…
The features and make up of the population of X-ray sources in Galactic star clusters reflect the properties of the underlying stellar environment. Cluster age, mass, stellar encounter rate, binary frequency, metallicity, and maybe other…