相关论文: Relativistic Electrons & Magnetic Fields in Cluste…
Observations with the RXTE and SAX satellites have recently led to the measurement of a second component in the spectra of several clusters of galaxies which are known to have regions of extended radio emission. This new component is quite…
Recent observations of high energy (> 20 keV) X-ray emission in a few clusters extend and broaden our knowledge of physical phenomena in the intracluster space. This emission is likely to be nonthermal, probably resulting from Compton…
Recent observations of high energy (> 20 keV) X-ray emission in a few clusters of galaxies broaden our knowledge of physical phenomena in the intracluster space. This emission is likely to be nonthermal, probably resulting from Compton…
Electrons at relativistic speeds, diffusing in magnetic fields, cause copious emission at radio frequencies in both clusters of galaxies and radio galaxies, through the non-thermal radiation emission called synchrotron. However, the total…
The most spectacular aspect of cluster radio emission is represented by the large-scale diffuse radio sources, which cannot be obviously associated with any individual galaxy. These sources demonstrate the existence of relativistic…
Relativistic electrons, seen in the large diffuse radio halo of the Coma cluster of galaxies, should scatter background photons to higher energies. We calculate the inverse Compton contributions from the microwave background, from the local…
The recent evidences of the presence of magnetic fields and relativistic particles in galaxy clusters are reviewed. The existence of microG-level magnetic fields in cluster atmospheres appears well established from the detection of diffuse…
Observed in a significant fraction of clusters and groups of galaxies, diffuse radio synchrotron emission reveals the presence of relativistic electrons and magnetic fields permeating large-scale systems of galaxies. Although these…
Models for the integrated relativistic electron population in clusters of galaxies are presented. The results depend on the history of electron acceleration in the cluster. If there is no present particle acceleration or other sources, then…
The intra-cluster medium of several galaxy clusters hosts large-scale regions of diffuse synchrotron radio emission, known as radio halos and relics, which demonstrate the presence of magnetic fields and relativistic electrons in clusters.…
We argue that the observed correlation between the radio luminosity and the X-ray luminosity in radio emitting galaxy clusters implies that the radio emission is due to secondary electrons that are produced by p-p interactions and lose…
The central regions of galaxy clusters are permeated by magnetic fields and filled with relativistic electrons. When clusters merge, the magnetic fields are amplified and relativistic electrons are re-accelerated by turbulence in the intra…
The cluster of galaxies A2256 was observed by the PCA and HEXTE experiments aboard the RXTE satellite during the period July 2001 - January 2002, for a total of 343 ks and 88 ks, respectively. Most of the emission is thermal, but the data…
We review observations of extended regions of radio emission in clusters; these include diffuse emission in `relics', and the large central regions commonly referred to as `halos'. The spectral observations, as well as Faraday rotation…
Evidence for nonthermal activity in clusters of galaxies is well established from radio observations of synchrotron emission by relativistic electrons, and new windows (in EUV and Hard X-ray ranges) have provided more powerful tools for its…
As energetic particles diffuse out of radio and star-forming galaxies (SFGs), their intracluster density builds up to a level that could account for a substantial part or all the emission from a radio halo. We calculate the particle…
A brief overview on the theory and observations of relativistic particle populations in clusters of galaxies is given. The following topics are addressed: (i) the diffuse relativistic electron population within the intra-cluster medium…
The existence of magnetic fields associated with the intracluster medium in clusters of galaxies is now well established through different methods of analysis. The most detailed evidence for the presence of cluster magnetic fields comes…
Most old distant radio galaxies should be extended X-ray sources due to inverse Compton scattering of Cosmic Microwave Background (CMB) photons. Such sources can be an important component in X-ray surveys for high redshift clusters, due to…
The main component of the intracluster medium (ICM) in clusters of galaxies is represented by the X-ray emitting thermal plasma. In addition, the presence of relativistic electrons and large-scale magnetic fields in a fraction of galaxy…