论文标题
早期型星系之间旋转支撑差异的起源：星系外的星系案例
Origin of the differences in rotational support among early-type galaxies: The case of galaxies outside clusters
论文作者
论文摘要
上下文：根据其恒星种群的有序旋转程度，将早期型星系（ETG）分为慢速和快速旋转器（FRS和SRS）。宇宙学水动力学模拟表明，在旋转支撑量减少之前，星系形成为FR，通常是由于合并而形成的。 目的：我们的目的是在观察群体外的星系上观察研究这一过程。 方法：我们利用了以下事实：不同的合并类型留下了不同的寿命痕迹。我们统计地分析了星系的多种特征，这些特征被预期会受到合并的影响，例如潮汐特征，运动学上不同的核心和出色的年龄。它们取自Matlas和Atlas $^\ Mathrm {3D} $数据库。通过多线性回归，我们确定了在银河系的固定质量和环境密度下的数量，与银河系的有序旋转的度量显着相关，$λ_{r_e}^n $。 结果：我们发现旋转支持与潮汐干扰和运动学亚结构的发生负相关，以及与金属性和金属性梯度的正相关。对于大型星系，旋转支撑与α元素的丰度和低密度环境中的星系呈负相关，它与中央光度尖端呈负相关。如果减少ETG的旋转支持的合并通常为较小，湿，并且发生在$ z \ 2 $的情况下，则这些和其他文献观察约束是最简单的。他们没有构成当前观察到的潮汐特征。观察到的潮汐特征的频率意味着每回合的合并速率为0.07-0.2。这不足以解释与合并红移一起观察到的ETG半径的生长。
Context: Early-type galaxies (ETGs) are divided into slow and fast rotators (FRs and SRs) according to the degree of ordered rotation of their stellar populations. Cosmological hydrodynamical simulations indicate that galaxies form as FRs before their rotational support decreases, usually because of mergers. Aims: We aimed to investigate this process observationally for galaxies outside of clusters. Methods: We made use of the fact that different merger types leave different traces that have different lifetimes. We statistically analyzed multiple characteristics of galaxies that are expected to be influenced by mergers, such as tidal features, kinematically distinct cores, and stellar ages. They were taken from the MATLAS and ATLAS$^\mathrm{3D}$ databases. Through multilinear regression we identified the quantities that, at a fixed mass and environmental density of the galaxy, significantly correlate with a measure of the ordered rotation of the galaxy, $λ_{R_e}^N$. Results: We found a negative correlation of the rotational support with the occurrence of tidal disturbances and kinematic substructures, and a positive correlation with metallicity and metallicity gradients. For massive galaxies, the rotational support correlates negatively with the abundance of alpha elements, and for the galaxies in low-density environments, it correlates negatively with the central photometric cuspiness. These and additional literature observational constraints are explained the easiest if the mergers that decreased the rotational support of ETGs were typically minor, wet, and happening at $z\approx 2$. They did not form the currently observed tidal features. The observed frequency of tidal features implies a merging rate of 0.07-0.2 per Gyr. This is insufficient to explain the observed growth of the radii of ETGs with redshift by mergers.
