Related papers: A Cold Front in a Preheated Galaxy Cluster
We have calculated the emergent X-ray properties for models of cluster cooling flows including the effects of accumulated cooled material. The opacity of this cooled gas can reduce the overall X-ray luminosity of the cooling flow, and…
The X-ray background intensity around Lick count galaxies and rich clusters of galaxies is investigated in three ROSAT energy bands. It is found that the X-ray enhancements surrounding concentrations of galaxies exhibit significantly softer…
We have used the ROSAT PSPC to study the properties of a sample of 24 X-ray bright galaxy groups, representing the largest sample examined in detail to date. Hot plasma models are fitted to the spectral data to derive temperatures, and…
When galaxy clusters collide, they generate shock fronts in the hot intracluster medium. Observations of these shocks can provide valuable information on the merger dynamics and physical conditions in the cluster plasma, and even help…
The thermodynamics of the diffuse, X-ray emitting gas in clusters of galaxies is linked to the entropy level of the intra cluster medium. In particular, models that successfully reproduce the properties of local X-ray clusters and groups…
Thermal gas in the center of galaxy clusters can show substantial motions that generate surface-brightness and temperature discontinuities known as cold fronts. The motions may be triggered by minor or off-axis mergers that preserve the…
We have performed a uniform analysis of 79 clusters of galaxies with the ROSAT HRI and ASCA to study the X-ray structure and evolution of clusters in the redshift range 0.1 < z < 1. We determined the average X-ray temperatures and the…
We study three prominent bi-modal X-ray clusters: A3528, A1750 and A3395. Using observations taken with ROSAT and ASCA, we analyze the temperature and surface brightness distributions. We also analyze the velocity distributions of the three…
In re-analyzing the archival Chandra data of the globular cluster 47 Tucanae, we have detected a new diffuse X-ray emission feature within the half-mass radius of the cluster. The spectrum of the diffuse emission can be described by a…
Central cool gas component that is often observed from a well-relaxed cluster system has long been interpreted as a consequence of ``Cooling Flow'' (CF), radiative cooling followed by inflow of Intra-Cluster Medium (ICM). However, recent…
The thermodynamics of the diffuse, X-ray emitting gas in clusters of galaxies is determined by gravitational processes associated with shock heating, adiabatic compression, and non-gravitational processes such as heating by SNe, stellar…
We present an X-ray image deprojection analysis of Einstein Observatory imaging data on 207, clusters of galaxies. The resulting radial profiles for luminosity, temperature, and electron density variations are determined from the cluster…
We discuss two themes from Chandra observations of galaxies and clusters. First, we describe the effects of radio-emitting plasmas or ``bubbles'', inflated by active galactic nuclei, on the hot X-ray emitting gaseous atmospheres in galaxies…
In this work, we report on a detailed simulation of the Bullet Cluster (1E0657-56) merger, including magnetohydrodynamics, plasma cooling, and adaptive mesh refinement. We constrain the simulation with data from gravitational lensing…
The number of diffuse radio halos in clusters of galaxies has grown in recent years, making it possible to derive statistical properties of these sources and of the hosting clusters. We show that diffuse sources are associated with X-ray…
The intracluster medium (ICM), composed of hot plasma, dominates the baryonic content of galaxy clusters and is primarily observable in X-rays. Its thermodynamic properties, pressure, temperature, entropy, and electron density, offer…
We investigate the growth over time of 20 massive (> 3 keV) clusters in a hydrodynamical simulation of the LambdaCDM cosmology with radiative cooling. The clusters show a variety of formation histories: some accrete most of their mass in…
We present results from a large mosaic of Suzaku observations of the Coma Cluster, the nearest and X-ray brightest hot, dynamically active, non-cool core system, focusing on the thermodynamic properties of the ICM on large scales. For…
Galaxy groups are key tracers of galaxy evolution, cluster evolution, and structure formation, yet they are difficult to study at even moderate redshift. We have undertaken a project to observe a flux-limited sample of intermediate-redshift…
We discuss the X-ray properties of the cooling flows in a sample of thirty highly X-ray luminous clusters of galaxies observed with the ASCA and ROSAT satellites. We demonstrate the need for multiphase models to consistently explain the…