发表机构
University of California, San Diego; San Diego State University; Princeton University（加州大学圣地亚哥分校; 圣地亚哥州立大学; 普林斯顿大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过Illustris-TNG50模拟发现，$R_{\rm{peri}}$可作为推断孤立矮星系恒星形成历史的可靠指标，揭示了孤立熄灭矮星系的子群划分及熄灭机制，其预测可通过Rubin LSST等巡天检验。
AI 中文摘要
近期发现的无持续恒星形成迹象的孤立矮星系（恒星质量${M}_{\rm{\star}}\sim 10^{7-9}\\,{\rm M}_{\odot}$），挑战了这些孤立系统完全是恒星形成星系的主流观点。研究孤立熄灭矮星系的起源，为揭示不同环境和恒星质量下驱动星系熄灭的主导过程提供了重要线索。本研究在Illustris-TNG50宇宙学模拟中识别出恒星质量${M}_{\star} \sim 10^{7-9}\\,{\rm M}_{\odot}$的中心矮星系，评估它们的恒星形成与轨道历史，并探究其暗物质晕属性如何与熄灭过程及与大质量近邻的相互作用相关联。我们发现，$R_{\rm{peri}}$（定义为中心矮星系与恒星质量${M}_{\star}> 10^{10}\\,{\rm M}_{\odot}$的星系曾达到的最近距离）是推断TNG50中中心矮星系恒星形成历史的可靠指标。我们还表明，孤立熄灭矮星系按$R_{\rm{peri}}$可分为反溅（backsplash）和非反溅两个子群，非反溅星系符合被宇宙网剥离或内部反馈机制熄灭的特征。此外，我们发现$R_{\rm{peri}}$与暗物质晕质量及基于晕最大圆周速度的恒星形成代理量存在强相关性，这些代理量常用于经验性星系-晕连接模型。这些预测可通过即将开展的深场宽视场巡天（如Rubin LSST和Roman）的数据进行检验，预计这些巡天将大幅增加矮星系的宇宙普查数量。
英文摘要
Recent discoveries of isolated dwarf galaxies (${M}_{\star}\sim 10^{7-9}~{\rm M}_{\odot}$) with no signs of ongoing star formation have challenged the prevailing notion that these solitary systems are exclusively star-forming. Investigating the origins of isolated quenched dwarfs provides important clues into the dominant processes driving galaxy quenching as a function of environment and stellar mass. In this study, we identify central dwarf galaxies in the Illustris-TNG50 cosmological simulation with ${M}_{\star} \sim 10^{7-9}~{\rm M}_{\odot}$, evaluate their star formation and orbital histories, and investigate how their dark matter halo properties correlate with quenching and interactions with massive neighbors. We find that $R_{\rm{peri}}$, defined as the closest separation ever attained between a central dwarf and a galaxy more massive than ${M}_{\star}> 10^{10}~{\rm M}_{\odot}$, is a reliable metric for inferring the star formation history of central dwarfs in TNG50. We also show that isolated quenched dwarf galaxies separate into backsplash and non-backsplash subpopulations as a function of $R_{\rm{peri}}$, and that non-backsplash galaxies are consistent with being quenched by cosmic web stripping or internal feedback mechanisms. Furthermore, we find that $R_{\rm{peri}}$ correlates strongly with dark matter halo mass and star formation proxies based on halo maximum circular velocity, which are commonly used in empirical galaxy-halo connection models. These predictions can be tested with data from upcoming deep and wide surveys (e.g., Rubin LSST and Roman) that are anticipated to significantly increase the cosmic census of dwarf galaxies.
Comments14 pages, 9 figures, submitted to OJAp, comments welcome
