Open AccessThe effect of radiative cooling on the X‐ray properties of galaxy clusters
Author(s) -
Pearce F. R.,
Thomas P. A.,
Couchman H. M. P.,
Edge A. C.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03773.x
Subject(s) - physics , radiative cooling , astrophysics , cooling flow , radiative transfer , galaxy cluster , cluster (spacecraft) , galaxy , baryon , dark matter , luminosity , optics , computer science , programming language
In this paper, we investigate the effect of cooling on the X‐ray properties of galaxy clusters. We have performed N ‐body, hydrodynamical simulations both with and without the effects of radiative cooling, but neglecting the effects of star formation and feedback. We show that radiative cooling produces an inflow of high‐entropy gas from the outer parts of the cluster, thus raising the cluster temperature and decreasing the X‐ray luminosity. With radiative cooling clusters are on average from three to five times less luminous in X‐rays than the same clusters simulated without cooling. However, we do not produce a large constant‐density core in either the gas or the dark matter distributions. Our results contradict previous work in which cooling raises the X‐ray luminosity and deposits an unreasonably large amount of mass in the central cluster galaxy. We achieve this by selecting our numerical resolution in such a way that a reasonable fraction of the baryonic material cools and by decoupling the hot and cold gas in our simulations, a first step towards modelling multiphase gas. We emphasize that globally cooling a sensible amount of material is vital and the presence or absence of massive central concentrations of cold baryonic material has a dramatic effect upon the resultant X‐ray properties of the clusters.