论文标题

SDSS-IV漫画:被动中央星系的恒星种群如何依赖于恒星和光晕质量

SDSS-IV MaNGA: How the stellar populations of passive central galaxies depend on stellar and halo mass

论文作者

Oyarzun, Grecco A., Bundy, Kevin, Westfall, Kyle B., Tinker, Jeremy L., Belfiore, Francesco, Argudo-Fernandez, Maria, Zheng, Zheng, Conroy, Charlie, Masters, Karen L., Wake, David, Law, David R., McDermid, Richard M., Aragon-Salamanca, Alfonso, Parikh, Taniya, Yan, Renbin, Bershady, Matthew, Sanchez, Sebastian F., Andrews, Brett H., Fernandez-Trincado, Jose G., Lane, Richard R., Bizyaev, D., Boardman, Nicholas Fraser, Lacerna, Ivan, Brownstein, J. R., Drory, Niv, Zhang, Kai

论文摘要

我们分析了2200个被动中央星系(Z〜0.05)的空间分析和共同添加的SDSS-IV漫画光谱,以了解中央星系组件如何依赖于恒星质量(M*)和Halo质量(MH)。我们通过使用Tinker(2020a,b)和广泛使用的Yang等人的新组目录来控制MH的系统错误。 (2007)目录。在固定的M*下,几种恒星吸收特征的强度随MH系统变化。这完全是无模型的,这是具有相同M*的恒星中心种群受其宿主光晕的特性影响的最初迹象之一。为了解释这些变化,我们使用代码ALF应用了完整的频谱拟合。在固定的M*下,更大的光晕中的中心较大,显示较低的[Fe/H],并且具有3.5 Sigma置信度的[mg/fe]较高。我们得出的结论是,光晕不仅决定了多少M*星系组装,还可以调节其化学富集史。在固定的MH上转到我们的分析,高m*中心较大,显示较低的[Fe/h],并且在MH> 10^{12} MSUN/H中具有较高的[mg/fe],并置信度> 4 Sigma。尽管人们认为大量的被动星系是早期和迅速形成的,但我们的结果是最早区分固定MH趋势的结果之一。他们认为,高m*中心通过增强的塌陷和气体加油经历了独特的早期形成历史,或者因为它们的光晕是早期形成且高度浓缩的,这可能是银河系偏置的信号。

We analyze spatially resolved and co-added SDSS-IV MaNGA spectra with signal-to-noise ~100 from 2200 passive central galaxies (z~0.05) to understand how central galaxy assembly depends on stellar mass (M*) and halo mass (Mh). We control for systematic errors in Mh by employing a new group catalog from Tinker (2020a,b) and the widely-used Yang et al. (2007) catalog. At fixed M*, the strength of several stellar absorption features varies systematically with Mh. Completely model-free, this is one of the first indications that the stellar populations of centrals with identical M* are affected by the properties of their host halos. To interpret these variations, we applied full spectral fitting with the code alf. At fixed M*, centrals in more massive halos are older, show lower [Fe/H], and have higher [Mg/Fe] with 3.5 sigma confidence. We conclude that halos not only dictate how much M* galaxies assemble, but also modulate their chemical enrichment histories. Turning to our analysis at fixed Mh, high-M* centrals are older, show lower [Fe/H], and have higher [Mg/Fe] for Mh>10^{12}Msun/h with confidence > 4 sigma. While massive passive galaxies are thought to form early and rapidly, our results are among the first to distinguish these trends at fixed Mh. They suggest that high-M* centrals experienced unique early formation histories, either through enhanced collapse and gas fueling, or because their halos were early-forming and highly concentrated, a possible signal of galaxy assembly bias.

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