Cosmological simulations of the intracluster medium

Kay, Scott T, Thomas, Peter A, Jenkins, Adrian and Pearce, Frazer R (2004) Cosmological simulations of the intracluster medium. Monthly Notices of the Royal Astronomical Society, 355 (4). pp. 1091-1104. ISSN 0035-8711

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Abstract

We investigate the properties of the intracluster medium (ICM) that forms within N-body/hydrodynamical simulations of galaxy clusters in a LambdaCDM cosmology. When radiative cooling and a simple model for galactic feedback are included, our clusters have X-ray luminosities and temperatures in good agreement with observed systems, demonstrating the required excess entropy in their cores. More generally, cooling and feedback increases the entropy of the ICM everywhere, albeit without significantly affecting the slope of the profile (S~r) at large radii. The temperature of the ICM is only modestly increased by these processes, with projected temperature profiles being in reasonable agreement with the observations. Star/galaxy formation is still too efficient in our simulations, however, and so our gas mass fractions are around 60 per cent of the observed value at r2500. Finally, we examine the reliability of using the hydrostatic equilibrium equation to estimate cluster masses and find that it underpredicts the true mass of our clusters by up to 20 per cent, due to incomplete thermalization of the gas. Feedback reduces this discrepancy, however, with estimates being accurate to within 10 per cent out to r500.

Item Type: Article
Additional Information: Kay was a PDRA and Thomas his supervisor: together they developed and refined the feedback models and wrote the paper. The others helped to carry out the simulations (32 citations).
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QC Physics
Depositing User: Peter Thomas
Date Deposited: 06 Feb 2012 20:45
Last Modified: 14 Mar 2017 00:18
URI: http://sro.sussex.ac.uk/id/eprint/27883

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