Related papers: Polarization Diagnostics for Cool Core Cluster Emi…
We present the detections of CO line emission in the central galaxy of sixteen extreme cooling flow clusters using the IRAM 30m and the JCMT 15m. These detections of CO(1-0), CO(2-1), CO(3-2) and CO(4-3) are consistent with the presence of…
Cold molecular gas has been recently detected in several cooling flow clusters of galaxies where huge optical nebulosities often stand. These optical filaments are tightly linked to the cooling flow and to the related phenomena, like the…
Cold molecular gas is found in several clusters of galaxies (Edge, 2001, Salome' & Combes, 2003): single dish telescope observations in CO(1-0) and CO(2-1) emission lines have revealed the existence of large amounts of cold gas (up to…
The cooling cores of clusters of galaxies are among the brightest thermal X-ray line sources in the universe. High resolution X-ray spectra would allow individual line fluxes to be measured. The fluxes of low ionization X-ray lines in…
The "sloshing" of the cold gas in the cores of relaxed clusters of galaxies is a widespread phenomenon, evidenced by the presence of spiral-shaped "cold fronts" in X-ray observations of these systems. In simulations, these flows of cold gas…
The excitation of the filamentary gas structures surrounding giant elliptical galaxies at the center of cool-core clusters, a.k.a BCGs (brightest cluster galaxies), is key to our understanding of active galactic nucleus feedback, and of the…
Massive galaxies in cooling flow clusters display clear evidence of feedback from Active Galactic Nuclei (AGN). Joint X-ray and radio observations have shown that AGN radio jets push aside the surrounding hot gas and form cavities in the…
Optical emission is detected from filaments around the central galaxies of clusters of galaxies. These filaments have lengths of tens of kiloparsecs. The emission is possibly due to heating caused by the dissipation of mechanical energy and…
Chandra X-ray observations revealed the presence of cold fronts (sharp contact discontinuities between gas regions with different temperatures and densities) in the centers of many, if not most, relaxed clusters with cool cores. We use…
We study non-thermal emissions from cool cores in galaxy clusters. We adopted a recent model, in which cosmic-rays (CRs) prevail in the cores and stably heat them through CR streaming. The non-thermal emissions come from the interaction…
Observations of the cores of nearby galaxy clusters show H$\alpha$ and molecular emission line filaments. We argue that these are the result of {\em local} thermal instability in a {\em globally} stable galaxy cluster core. We present…
Some bright cD galaxies in cluster cooling flows have Thomson optical depths exceeding 0.01. A few percent of their luminosity is scattered and appears as diffuse polarized emission. We calculate the scattering process for different…
On the basis of the universal gas fraction in clusters of galaxies, we estimate that the effective thermal conductivity required to balance radiative cooling in the cores, where the gas temperature is 3-10keV, is about one tenth of the…
In many clusters of galaxies there is evidence for cooling flows which deposit large quantities of cool gas in the central regions. A fraction of this gas might accumulate as dense cool clouds. The aim of this communication is to discuss…
We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from…
There is a strong spatial correlation between brightest cluster galaxies (BCGs) and the peak density and cooling rate of the intra-cluster medium (ICM). In this paper we combine integral field spectroscopy, CO observations and X-ray data 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…
We study the possibility that a large fraction of the gas at temperatures of \~10^7 K in cooling flow clusters cools by heat conduction to lower temperatures, rather than by radiative cooling. We argue that this process, when incorporated…
We present spatially resolved X-ray spectra taken with the EPIC cameras of XMM-Newton of a sample of 17 cooling clusters and three non-cooling clusters for comparison. The deprojected spectra are analyzed with a multi-temperature model,…
The physics of the coolest phases in the hot Intra-Cluster Medium (ICM) of clusters of galaxies is yet to be fully unveiled. X-ray cavities blown by the central Active Galactic Nucleus (AGN) contain enough energy to heat the surrounding gas…