Volume 570, October 2014
|Number of page(s)||16|
|Section||Cosmology (including clusters of galaxies)|
|Published online||31 October 2014|
Metal distribution in sloshing galaxy clusters: the case of A496⋆
1 INAF – Istituto di Astrofisica Spaziale e Fisica Cosmica - Milano, via E. Bassini 15, 20133 Milano, Italy
2 INAF – Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate (LC), Italy
Received: 16 April 2014
Accepted: 18 July 2014
We report results from a detailed study of the sloshing gas in the core of A496. We detected the low-temperature/entropy spiral feature found in several cores. We also found that conduction between the gas in the spiral and the ambient medium must be suppressed by more than one order of magnitude compared with the Spitzer conductivity. Intriguingly, while the gas in the spiral pattern features a higher metal abundance than the surrounding medium, it follows the relation of entropy vs metal abundance defined by gas outside the spiral. The most plausible explanation for this behavior is that the low-entropy metal-rich plasma that is lifted up through the cluster atmosphere by sloshing suffers little heating or mixing with the ambient medium. While sloshing appears to be capable of lifting up significant amount of gas, the limited heat exchange and mixing between gas within and outside the spiral implies that this mechanism is not at all effective in 1) permanently redistributing metals within the core region and 2) heating up the coolest and densest gas, thereby providing little or no contribution to the staving off of catastrophic cooling in cool cores.
Key words: galaxies: clusters: intracluster medium / X-rays: galaxies: clusters / galaxies: clusters: individual: A496
Appendices are available in electronic form at http://www.aanda.org
© ESO, 2014
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