Iron abundances and heating of the ICM in hydrodynamical simulations of galaxy clusters

R. Valdarnini

doi:10.1046/j.1365-8711.2003.06163.x

paper

Iron abundances and heating of the ICM in hydrodynamical simulations of galaxy clusters

arXiv:astro-ph/0210263 · doi:10.1046/j.1365-8711.2003.06163.x

Abstract

Results from a large set of hydrodynamical SPH simulations of galaxy clusters in a flat LCDM cosmology are used to investigate the metal enrichment and heating of the ICM. The physical modeling of the gas includes radiative cooling, star formation, energy feedback and metal enrichment that follow from the explosions of SNe of type II and Ia. The metallicity dependence of the cooling function is also taken into account. For a fiducial set of model prescriptions the results indicate radial iron profiles in broad agreement with observations; global iron abundances are also consistent with data. It is found that the iron distribution in the ICM is critically dependent on the shape of the metal deposition profile. For low temperatu re clusters simulations yield iron abundances below the allowed observational range, unless it is introduced a minimum diffusion length of metals in the ICM. The simulated emission-weighted radial temperature profiles are in good agreement with data for cooling flow clusters, but at very small distances from the cluster centres ( $\sim 2$ of the virial radii) the temperatures are a factor $\sim$ two higher than the measured spectral values. The luminosity-temperature relation is in excellent agreement with the data, cool clusters ( $T_{X} \sim 1 k e V$ ) have a core excess entropy of $\sim 200 k e V c m^{2}$ and their X-ray properties are unaffected by the amount of feedback energy that has heated the ICM. The fraction of hot gas $f_{g}$ at the virial radius increases with $T_{X}$ and the distribution obtained from the simulated cluster sample is consistent with the observational ranges.

arXiv comment29 pages, 5 tables, 8 figures, accepted for publication in MNRAS new version with small corrections to the values of M_200 in Table1

Iron abundances and heating of the ICM in hydrodynamical simulations of galaxy clusters

Abstract

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