Molecular gas as the driver of fundamental galactic relations
Molecular gas as the driver of fundamental galactic relations
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DOI：
10.1093/mnras/stv2121
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发表时间：
2015-07
影响因子：
4.8
通讯作者：
M. Bothwell;R. Maiolino;Yingjie Peng;C. Cicone;H. Griffith;J. Wagg
中科院分区：
文献类型：
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作者：
M. Bothwell;R. Maiolino;Yingjie Peng;C. Cicone;H. Griffith;J. Wagg
最近有很多工作致力于探索质量-金属丰度关系中的次级相关性，这些相关性与恒星形成速率和HI含量都有很大的关系。以前，分子气体数据的缺乏（再加上样本选择的偏差）阻碍了分子气体含量与分子气体含量之间关系的研究。在这项工作中，我们从红移范围0 < z < 2的各种调查中收集了221个星系的样本，以探索分子气体含量与金属丰度之间的联系。我们探讨了气体质量对质量-金属丰度关系的影响，发现该关系的偏移量与分子质量和总气体质量均呈负相关。然后，我们采用主成分分析技术来探索质量-金属丰度关系中的次级依赖关系，发现与气体质量的次级依赖关系明显强于与恒星形成速率的次级依赖关系，因此，潜在的“基本金属丰度关系”是恒星质量、金属丰度和气体质量之间的关系。特别是，通过Schmidt-Kennicutt关系，金属丰度对SFR的依赖仅仅是对分子气体含量依赖的副产品。最后，我们注意到我们的主成分分析发现气相金属丰度和恒星形成效率之间基本上没有联系。
There has been much recent work dedicated to exploring secondary correlations in the mass-metallicity relation, with significant dependence on both the star formation rate and HI content being demonstrated. Previously, a paucity of molecular gas data (combined with sample selection bias) hampered the investigation of any such relation with molecular gas content. In this work, we assemble a sample of 221 galaxies from a variety of surveys in the redshift range 0 < z < 2, to explore the connection between molecular gas content and metallicity. We explore the effect of gas mass on the mass-metallicity relation, finding that the offset from the relation is negatively correlated against both molecular and total gas mass. We then employ a principle component analysis technique to explore secondary dependences in the mass-metallicity relation, finding that the secondary dependence with gas mass is significantly stronger than with star formation rate, and as such the underlying `Fundamental Metallicity Relation' is between stellar mass, metallicity, and gas mass. In particular, the metallicity dependence on SFR is simply a byproduct of the dependence on the molecular gas content, via the Schmidt-Kennicutt relation. Finally, we note that our principle component analysis finds essentially no connection between gas-phase metallicity and the efficiency of star formation.