The relationship between cooling flows and metallicity measurements for X-ray-luminous clusters |
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| Authors: | S W Allen & A C Fabian |
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| Institution: | Institute of Astronomy, Madingley Road, Cambridge CB3 0HA |
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| Abstract: | 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. |
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| Keywords: | galaxies: clusters: general cooling flows intergalactic medium X-rays: galaxies |
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