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The metal enrichment of passive galaxies in cosmological simulations of galaxy formation
Title: | The metal enrichment of passive galaxies in cosmological simulations of galaxy formation |
Authors: | Okamoto, Takashi Browse this author →KAKEN DB | Nagashima, Masahiro Browse this author | Lacey, Cedric G. Browse this author | Frenk, Carlos S. Browse this author |
Keywords: | methods: numerical | galaxies: evolution | galaxies: formation |
Issue Date: | Feb-2017 |
Publisher: | Oxford University Press |
Journal Title: | Monthly notices of the royal astronomical society |
Volume: | 464 |
Issue: | 4 |
Start Page: | 4866 |
End Page: | 4874 |
Publisher DOI: | 10.1093/mnras/stw2729 |
Abstract: | Massive early-type galaxies have higher metallicities and higher ratios of a elements to iron than their less massive counterparts. Reproducing these correlations has long been a problem for hierarchical galaxy formation theory, both in semi-analytic models and cosmological hydrodynamic simulations. We show that a simulation in which gas cooling in massive dark haloes is quenched by radio-mode active galactic nuclei (AGNs) feedback naturally reproduces the observed trend between alpha/Fe and the velocity dispersion of galaxies, sigma. The quenching occurs earlier for more massive galaxies. Consequently, these galaxies complete their star formation before a/Fe is diluted by the contribution from Type Ia supernovae. For galaxies more massive than similar to 10(11)M(circle dot), whose alpha/Fe correlates positively with stellar mass, we find an inversely correlated mass-metallicity relation. This is a common problem in simulations in which star formation in massive galaxies is quenched either by quasar- or radio-mode AGN feedback. The early suppression of gas cooling in progenitors of massive galaxies prevents them from recapturing enriched gas ejected as winds. Simultaneously reproducing the [alpha/Fe]-sigma relation and the mass-metallicity relation is, thus, difficult in the current framework of galaxy formation. |
Rights: | This article has been accepted for publication in Monthly notices of the royal astronomical society © 2016 The Authors Published by Oxford University Press on behalf of The Royal Astronomical Society. All rights reserved. |
Type: | article |
URI: | http://hdl.handle.net/2115/65505 |
Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 岡本 崇
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