Related papers: Thermal conduction and reduced cooling flows in ga…
The role of thermal conduction in regulating the thermal behavior of cooling flows in galaxy clusters is reexamined. Recent investigations have shown that the anisotropic Coulomb heat flux caused by a magnetic field in a dilute plasma…
Recent observations by Chandra and XMM-Newton demonstrate that the central gas in "cooling flow" galaxy clusters has a mass cooling rate that decreases rapidly with decreasing temperature. This contrasts the predictions of a steady state…
Analyses of Chandra's first images of cooling flow clusters find smaller cooling rates than previously thought. Cooling may be occurring preferentially near regions of star formation in central cluster galaxies, where the local cooling and…
The radiative cooling time of the X-ray-emitting plasma near the center in many clusters of galaxies is shorter than the age of the cluster, but neither the expected large drop in central temperature --nor the expected mass flow towards the…
The gas temperature in the cores of many clusters of galaxies drops inward by about a factor of three or more within the central 100kpc radius. The radiative cooling time drops over the same region from 5 or more Gyr down to about 10^8 yr.…
We show that X-ray clusters would have cooled substantially over a Hubble time by transport of heat from their hot interior to the their envelope, if the heat conductivity had not been heavily suppressed relative to the Spitzer value due to…
The gas temperature in the cores of many clusters of galaxies drops inward by about a factor of three or more within the central 100 kpc radius. The radiative cooling time drops over the same region from 5 or more Gyr down to below a few…
In this Letter, we use the recent Chandra observation of A2142 reported by Markevitch et al. to put constraints on thermal conduction in the intracluster plasma. We show that the observed sharp temperature gradient requires that classical…
We discuss new results from the Chandra X-ray Observatory and XMM-Newton on cluster cooling flows, emphasizing early results from our Chandra programs. We find cooling rates reduced by factors of 5-10 compared to those from earlier…
We consider the impact of thermal conduction in clusters of galaxies on the (unmagnetized) interface between a cold gaseous cloud and a hotter gas flowing over the cloud (the so-called cold front). We argue that near the stagnation point of…
We investigate field-line separation in strong MHD turbulence using direct numerical simulations. We find that in the static-magnetic-field approximation the thermal conductivity in galaxy clusters is reduced by a factor of about 50…
The X-ray emission by hot gas at the centers of clusters of galaxies is commonly modeled assuming the existence of steady-state, inhomogeneous cooling flows. We derive the metallicity profiles of the intracluster medium expected from such…
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…
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…
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…
Unopposed radiative cooling in clusters of galaxies results in excessive mass deposition rates. However, the cool cores of galaxy clusters are continuously heated by thermal conduction and turbulent heat diffusion due to minor mergers or…
We examine the long-standing cooling flow problem in galaxy clusters with 3D MHD simulations of isolated clusters including radiative cooling and anisotropic thermal conduction along magnetic field lines. The central regions of the…
The radio continuum properties of galaxy clusters with cooling flows are reviewed along with the relationship to the X-ray environment. We find that 60-70% of cD galaxies in cooling flows are radio-loud, a much higher fraction than the 14%…
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…
It is generally argued that most clusters of galaxies host cooling flows in which radiative cooling in the centre causes a slow inflow. However, recent observations by Chandra and XMM conflict with the predicted cooling flow rates. It has…