Related papers: Radio Ghosts
We investigate the possibility that radio halos of clusters of galaxies are caused by synchrotron emission of cosmic ray electrons (CRe), which were produced by cosmic ray protons (CRp) interacting hadronically with the intra-cluster medium…
In this work we simulate the $50-200$ MHz radio sky that is constrained in the field of view ($5^{\circ}$ radius) of the 21 Centimeter Array (21CMA), by carrying out Monte-Carlo simulations to model redshifted cosmological reionization…
Clusters of galaxies, as the largest virialized systems in the Universe, are ideal laboratories to study the formation and evolution of cosmic structures...(abridged)... Most of the detailed knowledge of galaxy clusters has been obtained in…
Radio relics are arc-like synchrotron sources at the periphery of galaxy clusters, produced by cosmic-ray electrons in a $\mu$G magnetic field which are believed to have been (re-)accelerated by merger shock fronts. However, not all relics…
Diffuse radio sources in galaxy clusters are unique signposts of cluster assembly in the Universe. Our knowledge of their observational properties has considerably improved over the past decade, and the long standing questions concerning…
We take the established relation between black hole mass, X-ray luminosity, and radio luminosity and show that intermediate mass black holes, such as those predicted to exist at the centers of globular clusters, will be easily identifiable…
Radio galaxies are known to inflate lobes of hot relativistic plasmas into the intergalactic medium. Here we present hydrodynamical and magnetohydrodynamical simulations of these hot plasma bubbles in FRII objects. We focus on the later…
We present a combined radio/X-ray study of six massive galaxy clusters, aimed at determining the potential for heating of the intra-cluster medium (ICM) by non-central radio galaxies. Since X-ray cavities associated with the radio lobes of…
The cocoons surrounding powerful radio sources can be extensive if the jet that feeds the cocoon is light and supersonic. They have been shown to remain overpressured with respect to the ambient medium for most of the life time of the…
Galaxy clusters form through a sequence of mergers of smaller galaxy clusters and groups. Models of diffusive shock acceleration (DSA) suggest that in shocks that occur during cluster mergers, particles are accelerated to relativistic…
Radio emission in the direction of galaxy clusters is due to the individual emission of AGNs, and to the diffuse non-thermal emission of the intracluster medium (ICM). The population of AGNs in clusters is correlated to the overall halo…
During structure formation, energetic events and random motions of the hot gas residing inside galaxy clusters (the intracluster medium, ICM) generate turbulent motions. Radio diffuse emission probes the presence of magnetic fields and…
We review the properties and nature of luminous high-redshift radio galaxies (HzRGs, z > 2) and the environments in which they are located. HzRGs have several distinct constituents which interact with each other - relativistic plasma, gas…
We extend our earlier work on cluster cores with distinct radio bubbles, adding more active bubbles, i.e. those with Ghz radio emission, to our sample, and also investigating ``ghost bubbles,'' i.e. those without GHz radio emission. We have…
The Galactic disc is opaque to radio waves from extragalactic sources with frequencies nu less than ~3 MHz. However, radio waves with kHz, Hz, and even lower frequencies may propagate through the intergalactic medium (IGM). I argue that the…
Outflows up to 1500 km/s of atomic neutral hydrogen are detected in a growing number of radio galaxies. Outflows with similar velocities are also detected in ionized gas, suggesting a common origin for the extreme kinematics of these two…
Low-frequency radio observations are revealing an increasing number of diffuse synchrotron sources from galaxy clusters, dominantly in the form of radio halos or radio relics. The existence of this diffuse synchrotron emission indicates the…
Recent observations of galaxy clusters in radio and X-ray indicate that cosmic rays and magnetic fields may be energetically important in the intracluster medium. According to the estimates based on theses observational studies, the…
The thermal plasma of galaxy clusters lost most of its information on how structure formation proceeded as a result of dissipative processes. In contrast, non-equilibrium distributions of cosmic rays (CR) preserve the information about…
Gravitational interactions in rich clusters can strip material from the outer parts of galaxies or even completely disrupt entire systems, giving rise to large scale, low surface brightness ghostly features stretching across intergalactic…