论文标题

Yzics:使用相空间分析揭示簇星系的淬火历史

YZiCS: Unveiling Quenching History of Cluster Galaxies Using Phase-space Analysis

论文作者

Rhee, Jinsu, Smith, Rory, Choi, Hoseung, Contini, Emanuele, Jung, S. Lyla, Han, San, Yi, Sukyoung K.

论文摘要

我们使用了自从Yonsei Zoom-In群集模拟获得的星系中的(TSI)以来的时间,以及Sloan Digital Sky Survey(SDSS)数据版本10的恒星形成速率(SFR),以研究群集环境中磁盘星系的恒星形成的速度。我们首先确认模拟和观察到的星系始终分布在相空间中。然后,我们假设TSI和SFR是因果关系的。因此,相位空间位置处的星系的TSI和SFR都可以通过丰度匹配相关联。使用灵活的模型,我们得出了最能以$ z \ sim 0.08 $重现TSI和SFR之间关系的群集星系的恒星形成历史记录(SFH)。根据此SFH,我们发现带有$ M _ {*}> 10^{9.5} M _ {\ odot} $的星系通常遵循所谓的“延迟 - 然后 - 宽带”震动模式。我们的主要结果如下:(i)淬火的一部分是通过质量淬火和预处理进行的。此“ $ ex \ text { - } quenching阶段”的电子折叠时间尺度大约为3 gyr,具有强大的反质量依赖性。 (ii)在第一个越过群集中,大致将淬火的速度大致维持2 Gyr(“延迟时间”)。在延迟时间内,淬火可能保持温和,可能是因为气体损失主要发生在热气体和中性气体上。 (iii)在延迟时间后,淬火变得更加戏剧化(大约1 Gyr的电子折叠时间尺度),可能是因为RAM压力剥离在集群中心附近最强。违反直觉,更大的星系显示较短的淬火时间尺度,主要是因为它们由于$ ex \ text { - } situ $ quenching而以较低的气体分数进入簇。

We used the time since infall (TSI) of galaxies, obtained from the Yonsei Zoom-in Cluster Simulation, and the star formation rate (SFR) from the Sloan Digital Sky Survey (SDSS) Data Release 10 to study how quickly star formation of disk galaxies is quenched in cluster environments. We first confirm that both simulated and observed galaxies are consistently distributed in phase space. We then hypothesize that the TSI and SFR are causally connected; thus, both the TSI and SFR of galaxies at each position of phase space can be associated through abundance matching. Using a flexible model, we derive the star formation history (SFH) of cluster galaxies that best reproduces the relationship between the TSI and SFR at $z\sim 0.08$. According to this SFH, we find that the galaxies with $M_{*} > 10^{9.5} M_{\odot}$ generally follow the so-called "delayed-then-rapid" quenching pattern. Our main results are as following: (i) Part of the quenching takes place outside clusters through mass quenching and pre-processing. The e-folding timescale of this "$ex\text{-}situ$ quenching phase" is roughly 3 Gyr with a strong inverse mass dependence. (ii) The pace of quenching is maintained roughly for 2 Gyr ("delay time") during the first crossing time into the cluster. During the delay time, quenching remains gentle probably because gas loss happens primarily on hot and neutral gases. (iii) Quenching becomes more dramatic (e-folding timescale of roughly 1 Gyr) after delay time, probably because ram pressure stripping is strongest near the cluster center. Counter-intuitively, more massive galaxies show shorter quenching timescales mainly because they enter their clusters with lower gas fractions due to $ex\text{-}situ$ quenching.

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