Related papers: Evidence for radio-source heating of groups
ROSAT observations indicate that approximately half of all nearby groups of galaxies contain spatially extended X-ray emission. The radial extent of the X-ray emission is typically 50-500 kpc or approximately 10-50% of the virial radius of…
Two lines of evidence indicate that active galaxies, principally radio galaxies, have heated the diffuse hot gas in clusters. The first is the general need for additional heating to explain the steepness of the X-ray luminosity--temperature…
Recent observations of the interactions between radio sources and the X-ray-emitting gas in cooling flows in the cores of clusters of galaxies are reviewed. The radio sources inflate bubbles in the X-ray gas, which then rise buoyantly…
X-ray emission traces the gaseous environments of radio sources. The medium must be present for jet confinement, but what are its influence on jet fuelling, dynamics, propagation, and disruption? The observational situation is both…
The gas in the cores of many clusters and groups of galaxies has a short radiative cooling time. Energy from the central black hole is observed to flow into this gas by means of jets, bubbles and sound waves. Cooling is thus offset by…
We present the results of new XMM observations of FR-I and FR-II radio galaxies that show the importance of jet/environment interactions for both radio-source structure and the properties of the surrounding gas. The FR-I observations reveal…
We review some of the ways that X-ray observations provide unique information on radio galaxies. Thermal bremsstrahlung X-ray emission provides detailed data on ambient densities and temperatures. These parameters in turn can be used for…
Elliptical galaxies are generally luminous sources of X-ray radiation, and contain large amounts of hot, interstellar gas. In the brighter X-ray galaxies, the inferred masses of hot gas are consistent with those expected given the present…
X-shaped radio galaxies are defined by their peculiar large-scale radio morphology. In addition to the classical double-lobed structure they have a pair of low-luminosity wings that straddles the nucleus at almost right angles to the active…
Using Chandra imaging spectroscopy and VLA L-band maps, we have identified radio galaxies at P(1.4 GHz) >= 3x10^{23} W Hz^{-1} and X-ray point sources (XPSs) at L(0.3-8 keV) >= 10^{42} ergs s^{-1} in 11 moderate redshift (0.2<z<0.4)…
There is increasing evidence that some heating mechanism in addition to gravitational shock heating has been important for the hot gas inside clusters and groups of galaxies, as indicated by their observed X-ray scaling properties. While…
By combining the REFLEX and NORAS cluster datasets with the NVSS radio catalogue, we obtain a sample of 145, z<0.3, X-ray selected clusters brighter than 3 10^(-12) erg/s/cm^2 that show a central radio emission above 3 mJy. For virial…
Combining X-ray data from the ROSAT PSPC and optical data drawn from the literature, we examine in detail the relationship between the X-ray and optical properties of X-ray bright galaxy groups. We find a relationship between optical…
Chandra images of galaxy clusters have revealed a wealth of structure unseen by previous generations of low resolution X-ray observatories. In the cores of clusters, bright, irregular X-ray emission is now routinely seen within central…
X-ray selected galaxy group samples are usually generated by searching for extended X- ray sources that reflect the thermal radiation of the intragroup medium. On the other hand, large radio galaxies that regularly occupy galaxy groups also…
In our ongoing multi-wavelength study of cluster AGN, we find ~75% of the spectroscopically identified cluster X-ray point sources (XPS) with L(0.3-8.0keV)>10^{42} erg s^{-1} and cluster radio galaxies with P(1.4 GHz) > 3x10^{23} W Hz^{-1}…
A search for X-ray emission from compact groups revealed detection from 8 out of the 12 HCG images extracted from the ROSAT public archive. For two of them the X-ray emission originates from galaxies in the group. On the contrary, three…
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…
We present results from combined low-frequency radio and X-ray studies of nearby galaxy groups. We consider two main areas: firstly, the evolutionary process from spiral-dominated, HI-rich groups to elliptical-dominated systems with hot,…
In order to find the conditions which determine whether X-Ray hot gas in galaxy groups (intragroup gas; IGG) is heated externally or internally, we investigate the evolution of blast waves in galaxy groups growing on a hierarchical…