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arXiv 1603.04863astro-ph.GA
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$0.5\leq z\leq0.7$的恒星质量-气相金属丰度关系:向低质量区散射增加的幂律

Stellar Mass--Gas-phase Metallicity Relation at $0.5\leq z\leq0.7$: A Power Law with Increasing Scatter toward the Low-mass Regime

Yicheng Guo, David C. Koo, Yu Lu, John C. Forbes, Marc Rafelski, Jonathan R. Trump, Ricardo Amorín, Guillermo Barro, Romeel Davé, S. M. Faber, Nimish P. Hathi, … 展开作者

Yicheng Guo, David C. Koo, Yu Lu, John C. Forbes, Marc Rafelski, Jonathan R. Trump, Ricardo Amorín, Guillermo Barro, Romeel Davé, S. M. Faber, Nimish P. Hathi, Hassen Yesuf, Michael C. Cooper, Avishai Dekel, Puragra Guhathakurta, Evan N. Kirby, Anton M. Koekemoer, Pablo G. Pérez-González, Lihwai Lin, Jeffery A. Newman, Joel R. Primack, David J. Rosario, Christopher N. A. Willmer, Renbin Yan

摘要:

本文给出了1381个深源星系的恒星质量($M_{*}$)-气相金属丰度关系(MZR)及其在中等红移处的散射($0.5\leq z\leq0.7$)。恒星形成率(SFR)和颜色在一个给定的$M_{*}$的这个星等有限($R\lesssim24$ AB)的样本是正常的恒星形成星系的代表。对于质量低于$10^9 M_\odot$的星系,我们的237个星系的样本是$\sim$ 10倍,比以前的研究超出本地宇宙。样本量的巨大增加使MZR及其在低质量状态下的散射受到更好的约束。我们在$10^{8} M_\odot < M_{*} < 10^{11} M_\odot$:${12+log(O/H) = (5.83\pm0.19) + (0.30\pm0.02)log(M_{*}/M_\odot)}$中找到了一个幂律MZR。我们的MZR表现出良好的协议与其他人在类似的红移在文献中的中间和大规模的制度,但比其他人的MZR外推到质量低于$10^{9} M_\odot$。在我们的样本中,MZR的SFR依赖性比在本地星系中发现的要弱(称为基本金属丰度关系)。与各种理论模型相比,我们对低质量星系的MZR的斜率与纳入超新星能量驱动风的预测一致。作为强大的对目前不确定的金属丰度校准,散射的MZR作为一个强大的诊断的随机历史的气体吸积,气体再循环,和低质量星系的恒星形成。我们的主要结果是,我们的MZR的散射增加$M_{*}$减少。我们的结果意味着无论是重子吸积率的散射还是$M_{*}$ - $M_{halo}$关系的散射都随着$M_{*}$的减小而增大。此外,我们在$z=0.7$的散射措施似乎与本地星系的发现一致。

英文摘要:

We present the stellar mass ($M_{*}$)--gas-phase metallicity relation (MZR) and its scatter at intermediate redshifts ($0.5\leq z\leq0.7$) for 1381 field galaxies collected from deep spectroscopic surveys. The star formation rate (SFR) and color at a given $M_{*}$ of this magnitude-limited ($R\lesssim24$ AB) sample are representative of normal star-forming galaxies. For masses below $10^9 M_\odot$, our sample of 237 galaxies is $\sim$10 times larger than those in previous studies beyond the local universe. This huge gain in sample size enables superior constraints on the MZR and its scatter in the low-mass regime. We find a power-law MZR at $10^{8} M_\odot < M_{*} < 10^{11} M_\odot$: ${12+log(O/H) = (5.83\pm0.19) + (0.30\pm0.02)log(M_{*}/M_\odot)}$. Our MZR shows good agreement with others measured at similar redshifts in the literature in the intermediate and massive regimes, but is shallower than the extrapolation of the MZRs of others to masses below $10^{9} M_\odot$. The SFR dependence of the MZR in our sample is weaker than that found for local galaxies (known as the Fundamental Metallicity Relation). Compared to a variety of theoretical models, the slope of our MZR for low-mass galaxies agrees well with predictions incorporating supernova energy-driven winds. Being robust against currently uncertain metallicity calibrations, the scatter of the MZR serves as a powerful diagnostic of the stochastic history of gas accretion, gas recycling, and star formation of low-mass galaxies. Our major result is that the scatter of our MZR increases as $M_{*}$ decreases. Our result implies that either the scatter of the baryonic accretion rate or the scatter of the $M_{*}$--$M_{halo}$ relation increases as $M_{*}$ decreases. Moreover, our measures of scatter at $z=0.7$ appears consistent with that found for local galaxies.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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