大爆炸后10亿年银河系质量星系层级组装的早期步骤
Early steps in the hierarchical assembly of a Milky Way-mass galaxy 1 Gyr after the Big Bang
- Dunlap Institute for Astronomy and Astrophysics（邓拉普天体物理与天文研究所）
- Department of Astronomy and Physics and Institute for Computational Astrophysics, Saint Mary’s University（圣玛丽大学天文物理系及计算天体物理研究所）
- Waseda Research Institute for Science and Engineering, Faculty of Science and Engineering, Waseda University（早稻田大学理工学部理工学研究科）
- Kapteyn Astronomical Institute, University of Groningen（格罗宁根大学卡佩恩天文研究所）
- Faculty of Mathematics and Physics, University of Ljubljana（卢布尔雅那大学数学物理学院）
- Department of Physics and Astronomy, University of California Davis（加州大学戴维斯分校物理与天文学系）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
基于JWST观测，发现红移5.196处三个低质量星系正经历并合，其恒星质量增长因潮汐触发的恒星形成爆发而增强2.6倍，证实层级组装及相互作用诱导恒星形成是早期大质量星系形成的关键机制。
AI中文摘要：
我们报告了JWST对三个强透镜低质量星系（每个$M_\star \sim 10^{6-7} M_\odot$）组成的$z_{\rm spec}=5.196$致密群的观测，其较小的视线速度偏移（从$-120\pm100$到$+160\pm110$ km s$^{-1}$）和投影间距（$\sim2$ kpc）表明它们正在经历并合。基于丰度匹配论证，该三重星系群似乎注定在当今演化成一个银河系质量的星系。我们的分光光度分析表明，该系统的恒星质量增长并非仅仅由其组成部分的并合所致；相反，它被剧烈的恒星形成爆发大幅增强。这些恒星形成爆发可能由潮汐诱导的气体流入引发，将质量增长提升至现有恒星质量直接并合预期值的$2.6\pm0.5$倍。因此，这些光谱观测不仅证明了层级组装在当今大质量星系早期组装阶段仍是一条可行的形成通道，而且表明相互作用诱导的恒星形成爆发是该组装过程的主要加速器。
英文摘要：
We report JWST observations of a $z_{\rm spec}=5.196$ compact group of three strongly lensed low-mass galaxies ($M_\star \sim 10^{6-7} M_\odot$ each) whose small line-of-sight velocity offsets (from $-120\pm100$ to $+160\pm110$ km s$^{-1}$) and projected separations ($\sim2$ kpc) suggest that they are undergoing merging. On the basis of abundance-matching arguments, the trio appear to be destined to evolve into a Milky Way-mass galaxy by the present day. Our spectrophotometric analysis suggests that the stellar mass growth of this system is not simply just due to the merging of its components; rather, it is being dramatically enhanced by intense bursts of star formation. Presumably initiated by tidally-induced gas inflows, these star-forming bursts boost the mass growth $2.6\pm0.5$ times that expected in straightforward merging of the existing stellar masses. These spectroscopic observations thus not only demonstrate that hierarchical assembly remains a viable formation channel in the early assembly phases of present-day massive galaxy, but also that interaction-induced bursts of star formation are a major accelerator of this assembly process.
