Related papers: Cosmic rays and diffuse non-thermal emission in ga…
This paper presents a brief review of the current status of ultrahigh energy cosmic ray observations and discusses nearby starburst-like galaxies as their possible origin.
The sky distribution of cosmic rays with energies above the 'GZK cutoff' holds important clues to their origin. The AGASA data, although consistent with isotropy, shows evidence for small-angle clustering, and it has been argued that such…
Gamma-ray astronomy will play a crucial role in the investigation of nonthermal processes in the large scale structure of the universe. Particularly, galaxy clusters (GC) observations at this photon energy will help us understand the origin…
The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances…
This review discusses three ways in which radio galaxies and other high-redshift objects can give us information on the nature and statistics of cosmological inhomogeneities, and how they have evolved between high redshift and the present:…
Galaxy clusters form from the infall of dark and baryonic matter at the intersection of cosmic filaments. Most of the baryons are in the form of a hot, magnetized, intracluster plasma detected through its X-ray thermal bremsstrahlung…
1) Background: the budget of non-thermal energy in galaxy clusters is not well constrained, owing to the observational and theoretical difficulties in studying these diluted plasmas on large scales. 2) Method: we use recent cosmological…
A few, simple and qualitative examples of the potential of galaxy clusters as diagnostics of cosmology are presented. In relation to these we discuss briefly three ongoing or forthcoming cluster surveys in the optical/NIR, X-rays and the…
Recent international efforts have brought us closer to unveiling the century old mystery of the origin of cosmic rays. Cosmic ray, gamma ray, and neutrino observatories are reaching the necessary sensitivity to study the highest energy…
Cluster of galaxies are the largest concentrations of visible mass in the Universe and therefore a fundamental topic of cosmology and astrophysics. Recent radio, EUV, and X-ray observations suggest that clusters contain large populations of…
I briefly review our current knowledge of the non thermal emission from galaxy clusters and discuss future prospect with Simbol-X. Simbol-X will map the hard X-ray emission in clusters, determine its origin and disentangle the thermal and…
The gamma-ray observations of molecular clouds associated with supernova remnants are considered one of the most promising ways to search for a solution of the problem of cosmic ray origin. Here we briefly review the status of the field,…
In this contribution I present a review of star formation in clusters. I begin by discussing the various definitions of what constitutes a star cluster, and then compare the outcome of star formation (IMF, multiplicity, mass segregation and…
We show that cosmic rays in external galaxies, groups and clusters rich in gas, with an average flux similar to that observed in the Milky Way, could have produced the observed extragalactic diffuse gamma radiation.
The total cosmic-ray luminosity of the Galaxy is an important constraint on models of cosmic-ray generation. The diffuse high energy $\gamma$-ray and radio-synchrotron emissions of the Milky Way are used to derive this luminosity. The…
Clusters of galaxies are used in a variety of ways to do cosmology. Some of them are presented here. Their X-ray emitting gas allows us to determine the baryon fraction, dark matter distribution and the matter density $\Omega_{m}$ of the…
The origin of the highest-energy cosmic rays remains a mystery. The lack of a high energy cutoff in the cosmic ray spectrum together with an apparently isotropic distribution of arrival directions have strongly constrained most models…
A very interesting puzzle about the origin of electron and positron cosmic rays is deduced from the latests experimental results. We model the propagation of such cosmic rays in terms of a successfully tested two--zone propagation model.…
We aim to present a tutorial on the detection, parameter estimation and statistical analysis of compact sources (far galaxies, galaxy clusters and Galactic dense emission regions) in cosmic microwave background observations. The topic is of…
There is evidence that cosmic rays were present in galaxies at moderately high redshift. This suggests that magnetic fields were also present. If cosmic rays and magnetic fields must always be close to equipartition, as they are to an order…