Metal Transport in Galaxy Clusters by AGN Outbursts

Fulai Guo, UCSC

Abstract: X-ray observations of galaxy clusters indicate that the intracluster medium is strongly polluted by heavy metals and the spatial distribution of many metal elements (e.g., iron) is centrally peaked in many galaxy clusters, especially cool core (CC) clusters. In contrast, the metallicity profiles in many non-cool core (NCC) clusters are relatively flat. The origin of NCC clusters and their metallicity profiles is far from clear. Recent X-ray observations detect a handful of extremely powerful AGN outbursts in clusters. Using numerical hydrodynamic simulations, we show that such powerful AGN outbursts may transform a CC cluster to a NCC cluster, and also efficiently mix metals in cluster central regions, even removing central metallicity peaks if these peaks are not broad enough. For clusters with broad central abundance peaks, AGN outbursts decrease peak abundances, but can not effectively destroy the peaks. Our model thus simultaneously explain the contradictory (possibly bimodal) results of metallicity profiles in NCC clusters, some of which are nearly flat, while others have strong central peaks similar to those in CC clusters.

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