Related papers: The Intragroup versus the Intracluster Medium
We study the thermodynamic properties of the hot gas in a sample of groups in the 0.012-0.024 redshift range, using XMM-Newton observations. We present measurements of temperature, entropy, pressure and iron abundance. Non-parametric fits…
The luminous material in clusters of galaxies falls primarily into two forms: the visible galaxies and the X-ray emitting intra-cluster medium. The hot intra-cluster gas is the major observed baryonic component of clusters, about six times…
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…
Non-gravitational feedback affects the nature of the intra-cluster medium (ICM). X-ray cooling of the ICM and in situ energy feedback from AGN's and SNe as well as {\it preheating} of the gas at epochs preceding the formation of clusters…
We present results on the heating of the inter-cluster medium (ICM) by gravitational potential energy from in-falling satellites. We calculate the available excess energy of baryons once they are stripped from their satellite and added to…
[Abridged] The entropy distribution of the intracluster gas reflects both accretion history of the gas and processes of feedback which provide a further non-gravitational energy besides the potential one. In this work, we study the profiles…
The discrepancy between expected and observed cooling rates of X-ray emitting gas has led to the {\it cooling flow problem} at the cores of clusters of galaxies. A variety of models have been proposed to model the observed X-ray spectra and…
Efforts to understand the deviation of the L--T relation from a simple scaling law valid for clusters and groups have triggered a number of interesting studies on the subject. Techniques and approaches differ widely but most works agree on…
We conduct a joint X-ray and weak-lensing study of four relaxed galaxy clusters (Hydra A, A478, A1689 and A1835) observed by both Suzaku and Subaru out to virial radii, with an aim to understand recently-discovered unexpected feature of the…
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…
Observations of gravitational lensing indicate that the mass distribution in clusters of galaxies (where most of the mass is dark matter) is highly peaked towards the center, while X-ray observations imply that the gas is more extended. The…
(Abridged) Theoretical models that include only gravitationally-driven processes fail to match the observed mean X-ray properties of clusters. As a result, there has recently been increased interest in models in which either radiative…
Jets from supermassive black holes in the centres of galaxy clusters are a potential candidate for moderating gas cooling and subsequent star formation through depositing energy in the intra-cluster gas. In this work, we simulate the…
The strong deviation in the properties of X-ray clusters from simple scaling laws highlights the importance of non-gravitational heating and cooling processes in the evolution of proto-cluster gas. We investigate this from two directions:…
Using XMM-Newton spatially resolved X-ray imaging spectroscopy we obtain the temperature, density, entropy, gas mass, and total mass profiles for two groups of galaxies out to ~0.3 Rvir (Rvir, the virial radius). Our density profiles agree…
Semi-analytic models of X-ray clusters and groups of galaxies, relying on the idea that there was a non-gravitational energy injection in these systems, are able to reproduce many observed correlations, in particular the L_X-T relation and…
(Abridged) The thermal state of the intracluster medium results from a competition between gas cooling and heating. The heating comes from two distinct sources: gravitational heating from the collapse of the dark matter halo and thermal…
We provide an analytic framework for interpreting observations of multiphase circumgalactic gas that is heavily informed by recent numerical simulations of thermal instability and precipitation in cool-core galaxy clusters. We start by…
The evolution of the intergalactic medium (IGM) is influenced by gravitational collapse, radiative cooling, and baryonic feedback. Using cosmological hydrodynamic zoom-in simulations of a $8.83 \times 10^{12}$ M$_\odot$ group and a $2.92…
Galaxy groups and clusters are among the best probes of structure formation and growth in a cosmological context. Most of their baryonic component is dominated by the intracluster medium (ICM), whose thermodynamical properties serve as…