Metal Enrichment and Energetics of Galactic Winds in Galaxy Clusters

Hydrodynamical SPH simulations of galaxy clusters are used to investigate the metal enrichment of the intracluster medium. The final metallicity abundances of the simulated clusters are determined according to the numerical resolution and a number of model parameters. For a fiducial set of model prescriptions the results of the simulations indicate iron abundances in broad agreement with data. Final X-ray properties are not sensitive to the heating of the ICM. This supports a...

The presence of metals in hot cluster gas and in Ly-alpha absorbers, as well as the mass-metallicity relation of observed galaxies, suggest that galaxies lose a significant fraction of their metals to the intergalactic medium (IGM). Theoretical studies of this process have concentrated on metal removal by dynamical processes or supernova-driven winds. Here, we investigate the enrichment of the IGM by the expulsion of dust grains from galaxies by radiation pressure. We use alr...

The hot gas that fills the space between galaxies in clusters is rich in metals. In their large potential wells, galaxy clusters accumulate metals over the whole cluster history and hence they retain important information on cluster formation and evolution. We use a sample of 5 cool core clusters to study the distribution of metals in the ICM. We investigate whether the X-ray observations yield good estimates for the metal mass and whether the heavy elements abundances are co...

We present the analysis of deep X-ray observations of 10 massive galaxy clusters at redshifts $1.05 < z < 1.71$, with the primary goal of measuring the metallicity of the intracluster medium (ICM) at intermediate radii, to better constrain models of the metal enrichment of the intergalactic medium. The targets were selected from X-ray and Sunyaev-Zel'dovich (SZ) effect surveys, and observed with both the \textit{XMM-Newton} and \textit{Chandra} satellites. For each cluster, a...

We present a study of the effect of AGN feedback on metal enrichment and thermal properties of the intracluster medium (ICM) in hydrodynamical simulations. The cosmological simulations are performed for a set of clusters using a version of the TreePM-SPH Gadget code that follows chemo-dynamical evolution by accounting for metal enrichment by different stellar populations. Besides runs not including any efficient form of energy feedback, we carry out simulations including: (i)...

The enrichment of the intracluster medium (ICM) of galaxy clusters, within the framework of the supernovae-driven wind model for elliptical galaxies, has been considered under two extreme assumptions regarding the binding energy-mass-radius relations. Unless the binding energy at the time of wind commencement, for a given galactic mass, was a factor of approximately five lower than that predicted by the present-day relation, at most 20% of the ICM gas could have originated wi...

Groups and clusters contain a large fraction of hot gas which emits X-ray radiation. This gas yields information on the dynamical state and on the total mass of these systems. X-ray spectra show that heavy elements are present in the gas. As these metals must have been produced in the cluster/group galaxies and later transported into the gas, the metallicity is a good tracer for the transport processes. Several possible processes, that transport gas from the small potential w...

This paper discusses a semi-numerical method of investigating the enrichment of the intergalactic medium by galactic winds. We find that most galaxies at z >~ 3 should be driving winds, and that (if these winds are similar to those at low-z) these winds should escape to large distances. Our calculations -- which permit exploration of a large region of model parameter space -- indicate that the wind velocity, the mass of the wind-driving galaxies, the fraction of ambient mater...

The high metallicity of the intra-cluster medium (ICM) is generally interpreted on the base of the galactic wind scenario for elliptical galaxies. In this framework, we develop a toy-model to follow the chemical evolution of the ICM, formulated in analogy to chemical models for individual galaxies. The model computes the galaxy formation history (GFH) of cluster galaxies, connecting the final luminosity function (LF) to the corresponding metal enrichment history of the ICM. T...

It is frequently debated in literature whether a "standard" Initial Mass Function (IMF) - meaning an IMF of the kind usually adopted to explain the chemical evolution in the local Solar Neighbourhood - can account for the observed metal enrichment and Iron Mass-to-Light Ratio in clusters of galaxies. We address this problem by means of straightforward estimates that should hold independently of the details of chemical evolution models. It is crucial to compute self-consiste...