Title: Timescales for the Effects of Interactions on Galaxy Properties and SMBH Growth Show Chinese title

Title: 星系属性和超大质量黑洞增长受相互作用影响的时间尺度

Abstract: Galaxy interaction and merging have clear effects on the systems involved. We find an increase in the star formation rate (SFR), potential ignition of active galactic nuclei (AGN) and significant morphology changes. However, at what stage during interactions or mergers these changes begin to occur remains an open question. With a combination of machine learning and visual classification, we select a sample of 3,162 interacting and merging galaxies in the Cosmic Evolutionary Survey (COSMOS) field across a redshift range of 0.0 - 1.2. We divide this sample into four distinct stages of interaction based on their morphology, each stage representing a different phase of the dynamical timescale. We use the rich ancillary data available in COSMOS to probe the relation between interaction stage, stellar mass, SFR, and AGN fraction. We find that the distribution of SFRs rapidly change with stage for mass distributions consistent with being drawn from the same parent sample. This is driven by a decrease in the fraction of red sequence galaxies (from 17% as close pairs to 1.4% during merging) and an increase in the fraction of starburst galaxies (from 7% to 32%). We find the AGN fraction increases by a factor of 1.2 only at coalescence. We find the effects of interaction peak at the point of closest approach and coalescence of the two systems. We show that the point in time of the underlying dynamical timescale - and its related morphology - is as important to consider as its projected separation. Show Chinese abstract

Abstract: 星系相互作用和并合对所涉及的系统有明确的影响。我们发现恒星形成率（SFR）增加，活跃星系核（AGN）可能被点燃，并且显著的形态变化发生。然而，在相互作用或并合的哪个阶段这些变化开始发生仍然是一个开放的问题。通过机器学习与视觉分类的结合，我们在宇宙演化调查（COSMOS）场中选择了一个包含3162个相互作用和并合星系的样本，跨越了0.0到1.2的红移范围。我们根据它们的形态将这个样本分为四个不同的相互作用阶段，每个阶段代表动力学时间尺度的不同阶段。我们利用COSMOS中丰富的辅助数据来探讨相互作用阶段、恒星质量、SFR和AGN比例之间的关系。我们发现对于质量分布一致于从同一母样本抽取的样本，SFR的分布随着阶段迅速变化。这是由于红序列星系的比例下降（从作为近邻对时的17%降至并合时的1.4%）以及星爆星系的比例增加（从7%增至32%）。我们发现AGN比例仅在并合时增加了1.2倍。我们发现相互作用的影响在两个系统的最近接近点和并合时达到峰值。我们表明考虑潜在的动力学时间尺度及其相关的形态与考虑其投影分离同样重要。