Open AccessThe relationship between cooling flows and metallicity measurements for X‐ray‐luminous clusters
Author(s) -
Allen S. W.,
Fabian A. C.
Publication year - 1998
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.1365-8711.1998.01738.x
Subject(s) - cooling flow , metallicity , physics , astrophysics , surface brightness , intracluster medium , rosat , galaxy , galaxy cluster , cluster (spacecraft) , brightness , spectroscopy , emission spectrum , spectral line , astronomy , computer science , programming language
We explore the relationship between the metallicity of the intracluster gas in clusters of galaxies, determined by X‐ray spectroscopy, and the presence of cooling flows. Using ASCA spectra and ROSAT images, we demonstrate a clear segregation between the metallicities of clusters with and without cooling flows. On average, cooling‐flow clusters have an emission‐weighted metallicity a factor ∼ 1.8 times higher than that of non‐cooling‐flow systems. We suggest that this is caused by the presence of metallicity gradients in the cooling‐flow clusters, coupled with the sharply peaked X‐ray surface brightness profiles of these systems. Non‐cooling‐flow clusters have much flatter X‐ray surface brightness distributions and are thought to have undergone recent merger events, which may have mixed the central high‐metallicity gas with the surrounding less metal‐rich material. We find no evidence for evolution in the emission‐weighted metallicities of clusters within z ∼ 0.3.