标题： KMOS星系团调查（KCS）第三部分：JKCS 041中$z \simeq 1.80$附近星系团的本原平面 显示英文标题

标题： The KMOS Cluster Survey (KCS) III: fundamental plane of cluster galaxies at $z \simeq 1.80$ in JKCS 041

摘要： 我们提供了16个星系在超密度JKCS 041中的数据，$z \simeq 1.80$作为K波段多目标光谱仪（KMOS）星系团调查（KCS）的一部分。 通过20小时的积分，我们获得了深度吸收线光谱，从中推导出七个静止星系的速度弥散。 我们将从哈勃空间望远镜图像中得出的光度参数与速度弥散结合，为JKCS 041中的静止星系构建了一个基本平面（FP）。 从FP的零点演化中，我们推导出这些星系的形成红移为$z_{form} = 3.0\pm0.3$，对应平均年龄为$1.4\pm0.2$吉年。 我们测试了结构和速度弥散演化对FP零点的影响，发现使用动力学质量归一化参数（$\sim 3\%$）时贡献可以忽略不计，但使用恒星质量归一化参数（$\sim 42 \%$）时贡献显著。 从星系的相对速度出发，我们研究了这16个确认成员在JKCS 041中的三维结构，并发现超密度西南部的一个星系群具有系统更高的速度。 我们从FP中推导出不同组中星系的年龄。 我们发现向东延伸的星系群通常比西南部星系群（$0.3\pm0.2$亿年）的星系更老（$2.1\substack{+0.3\\-0.2}$亿年）。 尽管基于样本数量较小，但超密度的动力学、形态和年龄结果可能表明JKCS 041正在形成，并可能由两个正在合并的星系群组成。 这一结果首次将大尺度结构与该红移下星系的年龄联系起来。 显示英文摘要

摘要： We present data for 16 galaxies in the overdensity JKCS 041 at $z \simeq 1.80$ as part of the K-band Multi-Object Spectrograph (KMOS) Cluster Survey (KCS). With 20-hour integrations, we have obtained deep absorption-line spectra from which we derived velocity dispersions for seven quiescent galaxies. We combined photometric parameters derived from Hubble Space Telescope images with the dispersions to construct a fundamental plane (FP) for quiescent galaxies in JKCS 041. From the zero-point evolution of the FP, we derived a formation redshift for the galaxies of $z_{form} = 3.0\pm0.3$, corresponding to a mean age of $1.4\pm0.2$ Gyrs. We tested the effect of structural and velocity dispersion evolution on our FP zero point and found a negligible contribution when using dynamical mass-normalized parameters ($\sim 3\%$), but a significant contribution from stellar-mass-normalized parameters ($\sim 42 \%$). From the relative velocities of the galaxies, we probed the three-dimensional structure of these 16 confirmed members of JKCS 041, and found that a group of galaxies in the south west of the overdensity had systematically higher velocities. We derived ages for the galaxies in the different groups from the FP. We found the east-extending group had typically older galaxies ($2.1\substack{+0.3\\-0.2}$ Gyrs), than those in the south-west group ($0.3\pm0.2$ Gyrs). Although based on small numbers, the overdensity dynamics, morphology, and age results could indicate that JKCS 041 is in formation and may comprise two merging groups of galaxies. The result could link large-scale structure to ages of galaxies for the first time at this redshift.