The relationship between cooling flows and metallicity measurements for X-ray-luminous clusters
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.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 1998
- DOI:
- 10.1046/j.1365-8711.1998.01738.x
- arXiv:
- arXiv:astro-ph/9802219
- Bibcode:
- 1998MNRAS.297L..63A
- Keywords:
-
- GALAXIES: CLUSTERS: GENERAL;
- COOLING FLOWS;
- INTERGALACTIC MEDIUM;
- X-RAYS: GALAXIES;
- Astrophysics
- E-Print:
- Submitted to MNRAS letters (December 1997). 6 pages, 2 figures in MNRAS LaTex style. Minor revisions