Related papers: X-rays from Open Clusters
With rapid improvements in the assembly of large samples of galaxy clusters, we are approaching the ability to study clusters at $z\gtrsim2$. Evolutionary studies comparing these distant clusters to the clusters in our local universe depend…
Over half the 3CRR sample of radio galaxies and quasars has been observed in X-rays with ROSAT pointed observations, and we present results from these observations, discussing many of the sources in detail. The improved spatial resolution…
We discuss the rationale and the present status of a large redshift survey aiming at measuring distances for all the clusters of galaxies detected by the ROSAT X--ray All--Sky Survey in the southern hemisphere, with flux larger than $\sim…
X-ray emission from stars in the cool half of the Hertzsprung-Russell diagram is generally attributed to the presence of a magnetic corona that contains plasma at temperatures exceeding 1 million K. Coronae are ubiquitous among these stars,…
We have conducted a systematic search for supersoft X-ray sources using the ROSAT all-sky survey data. With the optical identification of the selected sources being almost complete, we discuss the statistics of the various source classes…
We present a statistical study of the occurrence and effects of the cooling cores in the clusters of galaxies in a flux-limited sample, HIFLUGCS, based on ROSAT and ASCA observations. About 49% of the clusters in this sample have a…
We present the results of an X-ray follow-up campaign targeting 10 Weak Lensing (WL) selected galaxy clusters from a Subaru WL survey. Eight clusters were studied with dedicated Chandra pointings, whereas archival X-ray data were used for…
We use the Fifth Data Release of the Sloan Digital Sky Survey to study X-ray-selected galaxy groups and compare their properties to clusters. We search for infall patterns around the groups and use these to measure group mass profiles to…
Context. Scaling relations between cluster properties embody the formation and evolution of cosmic structure. Intrinsic scatters and correlations between X-ray properties are determined from merger history, baryonic processes, and dynamical…
It is suggested that the three-segmented morphology of the soft X-ray emission from cluster and field stars may be understood in terms of the recent classification of rotating stars into three kinds: those lying on the convective sequence,…
Results of a study of the theoretically predicted and observed X-ray properties of local massive star clusters are presented, with a focus on understanding the mass and energy flow from these clusters into the ISM via a cluster wind. A…
Recent results on cluster cooling flows are reviewed. Observations of excess soft X-ray provides the only direct evidence for a major repository for the cooled gas. Unfortunately, the frequency of occurrence of large excess columns is…
Clusters of galaxies are studied from a theoretical point of view, comparing with observational results whenever possible. The problem is approached both analytically as well as by means of high-resoultion numerical simulations. The dark…
We use gas-dynamical simulations of galaxy clusters to compare their X-ray and strong lensing properties. Special emphasis is laid on mass estimates. The cluster masses range between 6 x 10^14 solar masses and 4 x 10^15 solar masses, and…
We present optical identification and high-resolution spectroscopy of ROSAT sources in the field of the old open cluster M 67. For the first time it is possible to analyze coronal and chromospheric activity of active stars in a solar-age…
In the last eight years, the Chandra and XMM-Newton satellites changed significantly our view of X-ray clusters of galaxies. In particular, several complex phenomena have been directly observed: interactions between cluster galaxies and the…
We present a new model for the X-ray properties of the intracluster medium that explicitly includes heating of the gas by the energy released during the evolution of cluster galaxies. We calculate the evolution of clusters by combining the…
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…
We present an analysis of the X-ray emission for a complete sample of 288 Abell clusters spanning the redshift range 0.016<= z <= 0.09 from the ROSAT All-Sky Survey. This sample is based on our 20cm VLA survey of nearby Abell clusters. We…
The detection of clusters of galaxies in large surveys plays an important part in extragalactic astronomy, and particularly in cosmology, since cluster counts can give strong constraints on cosmological parameters. X-ray imaging is in…