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arXiv 1802.09560astro-ph.GA
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恒星质量的演化--金属丰度关系-- I:z~0.4星系团Cl0024中的半乳糖醛酸

Evolution of the Stellar Mass--Metallicity Relation - I: Galaxies in the z~0.4 Cluster Cl0024

Nicha Leethochawalit, Evan N. Kirby, Sean M. Moran, Richard S. Ellis, Tommaso Treu

摘要:

利用静止星系的全谱恒星星族综合模型,给出了Cl 0024 +1654星系团在z~0.4处的恒星质量-恒星金属丰度关系(MZR).我们的恒星质量范围的下限是$M_*=10^{9.7}M_\odot$,这是在本地宇宙之外测量到的单个恒星金属丰度的最低星系质量。我们报告的恒星MZR观测到的红移在$0.037\pm0.007$德克斯每陀螺仪的演变检测,符合流体动力学模拟的预测。此外,我们发现恒星MZR随观测到的红移的演化可以用恒星MZR随其形成时间的演化来解释,即,当考虑星系的单个恒星星族(SSP)等效年龄时,我们得到了一个很好的结果。这种行为与由气体形成的恒星是一致的,这些恒星也有一个标准化的MZR,随着红移而减少。最后,我们发现,在所观察到的质量范围内,MZR可以描述为一个线性函数与一个浅的斜率,($[Fe/H] \propto (0.16 \pm 0.03) \log M_*$)。斜率表明星系反馈,在质量加载因子方面,可能在观测到的质量和红移范围内与质量无关。

英文摘要:

We present the stellar mass-stellar metallicity relationship (MZR) in the Cl0024+1654 galaxy cluster at z~0.4 using full spectrum stellar population synthesis modeling of individual quiescent galaxies. The lower limit of our stellar mass range is $M_*=10^{9.7}M_\odot$, the lowest galaxy mass at which individual stellar metallicity has been measured beyond the local universe. We report a detection of an evolution of the stellar MZR with observed redshift at $0.037\pm0.007$ dex per Gyr, consistent with the predictions from hydrodynamical simulations. Additionally, we find that the evolution of the stellar MZR with observed redshift can be explained by an evolution of the stellar MZR with their formation time, i.e., when the single stellar population (SSP)-equivalent ages of galaxies are taken into account. This behavior is consistent with stars forming out of gas that also has an MZR with a normalization that decreases with redshift. Lastly, we find that over the observed mass range, the MZR can be described by a linear function with a shallow slope, ($[Fe/H] \propto (0.16 \pm 0.03) \log M_*$). The slope suggests that galaxy feedback, in terms of mass-loading factor, might be mass-independent over the observed mass and redshift range.

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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