Related papers: Entropy Limit and the Cold Feedback Mechanism in C…
In the cores of some galaxy clusters the hot intracluster plasma is dense enough that it should cool radiatively in the cluster's lifetime, leading to continuous "cooling flows" of gas sinking towards the cluster center, yet no such cooling…
We analyze two time-dependent cluster cooling flow models in spherical symmetry. The first assumes that the intracluster gas resides in a static external potential, and includes the effects of optically thin radiative cooling and mass…
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…
Most elliptical galaxies contain central black holes (BHs), and most also contain significant amounts of hot gas capable of accreting on to the central BH due to cooling times short compared to the Hubble time. Why therefore do we not see…
Recent data have radically altered the X-ray perspective on cooling flow clusters. X-ray spectra show that very little of the hot intracluster medium is cooler than about 1 keV, despite having short cooling times. In an increasing number of…
The state of the hot gas in clusters of galaxies is investigated with a set of model clusters, created by assuming a polytropic equation of state (Gamma=1.2) and hydrostatic equilibrium inside gravitational potential wells drawn from a dark…
Shortly after the first results of Chandra and XMM-Newton appeared, many researchers in the field abandoned the term "cooling flow clusters" in favor of the name "cool core clusters". This change, I argue, has been causing damage by…
In the outskirts of galaxy clusters, entropy profiles measured from X-ray observations of the hot intracluster medium (ICM) drops off unexpectedly. One possible explanation for this effect is gas clumping, where pockets of cooler and denser…
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 investigate the properties of cool cores in an optimally selected sample of 37 massive and X-ray-bright galaxy clusters, with regular morphologies, observed with Chandra. We measured the density, temperature, and abundance radial…
We present an analysis of the growth of black holes through accretion and bulges through star formation in 33 galaxies at the centers of cooling flows. Most of these systems show evidence of cavities in the intracluster medium (ICM)…
The hot intracluster medium (ICM) is thought to be quiescent with low observed velocity dispersions. Surface brightness fluctuations of the ICM also suggest that its turbulence is subsonic with a Kolmogorov scaling relation, indicating that…
We discuss hydrostatic models of galaxy clusters in which heat diffusion balances radiative cooling. We consider two different sources of diffusion, thermal conduction and turbulent mixing, parameterized by dimensionless coefficients, f and…
We investigate the relationship between X-ray cooling and star formation in brightest cluster galaxies (BCGs). We present an X-ray spectral analysis of the inner regions, 10-40 kpc, of six nearby cool core clusters (z<0.35) observed with…
We present a spherically-symmetric, steady-state model of galaxy clusters in which radiative cooling from the hot gas is balanced by heat transport through turbulent mixing. We assume that the gas is in hydrostatic equilibrium, and describe…
Cooling flows are common in galaxy clusters which have cool cores. The soft X-ray emission below 1 keV from the flows is mostly absorbed by cold dusty gas within the central cooling sites. Further evidence for this process is presented here…
Studies of the X-ray surface brightness profiles of clusters, coupled with theoretical considerations, suggest that the breaking of self-similarity in the hot gas results from an `entropy floor', established by some heating process, which…
We perform linear analysis of thermal instability in a contracting large cloud filled with warm HI gas and investigate the effect of metallicity and radiation flux. When the cloud reaches critical density n_f, the cloud fragments into cool,…
We have obtained deep, high spatial and spectral resolution, long-slit spectra of the Halpha nebulae in the cool cores of 9 galaxy clusters. This sample provides a wealth of information on the ionization state, kinematics, and reddening of…
Using a combination of deep 574ks Chandra data, XMM-Newton high-resolution spectra, and optical Halpha+NII images, we study the nature and spatial distribution of the multiphase plasma in M87. Our results provide direct observational…