Related papers: Frequently Asked Questions on the Luminosity--Temp…
The new era of high-resolution X-ray spectroscopy will significantly improve our understanding of the intra-cluster medium (ICM) by providing precise constraints on its underlying physical properties. However, spectral fitting requires…
Using a sample of ten nearby (z< 0.15), relaxed galaxy clusters in the temperature range [2-9] keV, we have investigated the scaling relation between the mass at various density contrasts (delta=2500,1000,500,200) and the cluster…
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…
Assuming that there exists a species of heavy sterile neutrinos($m_{\nu}>1$ keV) and their decays can serve as a heating source of the hot gas in galaxy clusters, we study how the observational constraints on cooling flow limit the mass of…
In-medium modifications of light cluster properties in warm stellar matter are studied within the relativistic mean-field approximation. In-medium effects are included by introducing an explicit binding energy shift analytically calculated…
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…
The properties of X-ray clusters of galaxies can be well understood in terms of a competition between shock heating and adiabatic compression. Strong shocks are expected to be important for massive clusters, while adiabatic compression is…
The temperature and density of the hot diffuse medium pervading galaxy groups and clusters combine into one significant quantity, the entropy. Here we express the entropy levels and profiles in model-independent forms by joining two…
The X-ray luminosity and temperature of clusters and groups of galaxies do not scale in a self-similar manner. This has often been interpreted as a sign that the intracluster medium has been substantially heated by non-gravitational…
We present a detailed investigation of the X-ray luminosity (Lx)-gas temperature (Tvir) relation of the complete X-ray flux-limited sample of the 64 brightest galaxy clusters in the sky (HIFLUGCS). We study the influence of two…
The influence of cool galaxy cluster cores on the X-ray luminosity--gravitational mass relation is studied with Chandra observations of 64 clusters in the HIFLUGCS sample. As preliminary results we find (i) a significant offset of cool core…
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 report the results of recent numerical simulations of the head-on merger of a cooling flow cluster with an infalling subcluster of galaxies. These simulations examined the effects of different types of cluster mergers (with 16:1 and 4:1…
We derive constraints on the mass-temperature relation of galaxy clusters from their observed luminosity-temperature relation and X-ray temperature function. Adopting the isothermal gas in hydrostatic equilibrium embedded in the universal…
(Abridged) X-ray clusters are conventionally divided into two classes: "cool core" (CC) clusters and "non-cool core" (NCC) clusters. Yet relatively little attention has been given to the origins of this dichotomy and, in particular, to the…
We study the evolution of two fundamental properties of galaxy clusters: the luminosity function (LF) and the scaling relations between the total galaxy number N (or luminosity) and cluster mass M. Using a sample of 27 clusters (0<z<0.9)…
Galaxy clusters exhibit regular scaling relations among their bulk properties. These relations establish vital links between halo mass and cluster observables. Precision cosmology studies that depend on these links benefit from a better…
The relationship between the X-ray determined temperature $T$ of the intracluster gas and the optical measured velocity dispersion $\sigma$ of the cluster galaxies is often believed to be not only a straightforward but also robust test for…
Using Chandra data for a sample of 26 galaxy groups, we constrained the central cooling times (CCTs) of the ICM and classified the groups as strong cool-core (SCC), weak cool-core (WCC) and non-cool-core (NCC) based on their CCTs. The total…
Within the standard framework of structure formation, where clusters and groups of galaxies are built up from the merging of smaller systems, the physical properties of the intracluster medium, such as the gas temperature and the total…