http://arxiv.org/abs/1707.05318
The distribution of metals in the intra-cluster medium encodes important information about the enrichment history and formation of galaxy clusters. Here we explore the metal content of clusters in IllustrisTNG – a new suite of galaxy formation simulations building on the Illustris project. Our cluster sample contains 20 objects in TNG100 – a ~(100 Mpc)^3 volume simulation with 2×1820^3 resolution elements, and 370 objects in TNG300 – a ~(300 Mpc)^3 volume simulation with 2×2500^3 resolution elements. The z=0 metallicity profiles agree with observations, and the enrichment history is consistent with observational data going beyond z~1, showing nearly no metallicity evolution. The abundance profiles vary only minimally within the cluster samples, especially in the outskirts with a relative scatter of ~15%. The average metallicity profile flattens towards the center, where we find a logarithmic slope of -0.1 compared to -0.5 in the outskirts. Cool core clusters have more centrally peaked metallicity profiles (~0.8 solar) compared to non-cool core systems (~0.5 solar), similar to observational trends. Si/Fe and O/Fe radial profiles follow positive gradients as the ratios of type Ia over core-collapse supernovae increase towards cluster centres. The outer abundance profiles do not evolve below z~2, whereas the inner profiles flatten towards z=0. More than ~80% of the metals in the intra-cluster medium have been accreted from the proto-cluster environment, which has been enriched to ~0.1 solar already at z~2. We conclude that the intra-cluster metal distribution is uniform among our cluster sample, nearly time-invariant in the outskirts for more than 10 Gyr, and forms through a universal enrichment history.
M. Vogelsberger, F. Marinacci, P. Torrey, et. al.
Wed, 19 Jul 17
41/58
Comments: 21 pages, 16 figures. Submitted to MNRAS. The IllustrisTNG project website can be found at this http URL
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