发表机构
University of Sussex; DISCnet Centre for Doctoral Training, University of Sussex; University of Bath; Kavli Institute for Cosmological Physics, University of Chicago; Institut d’Astrophysique de Paris, Sorbonne Université, CNRS; University of Oxford（萨塞克斯大学; 萨塞克斯大学 DISCnet 博士培训中心; 巴斯大学; 芝加哥大学卡弗里宇宙物理学研究所; 巴黎天体物理研究所，索邦大学，法国国家科学研究中心; 牛津大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
利用MEGATRON模拟研究再电离纪元矮星系恒星形成间歇循环，发现反馈方案调控淬灭频率与质量依赖，淬灭机制分机械排空与热力学抑制两种，并影响观测选择效应。
AI 中文摘要
在再电离纪元期间，低质量星系预计会以短暂爆发形式形成恒星，爆发之间间隔着不活跃期，但什么机制调控这一循环，以及它对恒星反馈建模的敏感程度，目前仍不清楚。我们使用MEGATRON高红移放大模拟套件，其中四种恒星形成与恒星反馈方案从相同的初始条件演化而来，以研究在$z = 8.5$时，$M_{*} \sim 10^{4} - 10^{8} M_{\odot}$范围内星系恒星质量增长的调控机制。我们将星系分类为恒星形成型、迷你淬灭型（过去10 Myr内无显著恒星形成）或淬灭型（过去100 Myr内无显著恒星形成）。反馈方案既决定了星系处于静止状态的频率，也决定了这种频率如何依赖于质量。与基准模型和变化IMF模型相比，具有更强或更聚集反馈的模型产生了更大的静止星系比例。在固定质量下，不同模型之间的占空比也相差数倍。淬灭星系的冷气体轮廓与两种物理上不同的淬灭模式一致：机械气体排空，产生紧凑、冷气体贫乏的系统；以及热力学抑制，保留冷但恒星形成不活跃的气体储库。在这些质量下，静止星系低于未放大JWST/NIRCam的探测极限，而相同质量的恒星形成星系则不然，因此通量限制样本将偏向于活跃阶段。在透镜场中测量作为恒星质量函数的静止星系比例，将为宇宙黎明时期的恒星反馈模型提供直接检验。
英文摘要
Low-mass galaxies during the Epoch of Reionization are expected to form stars in short bursts separated by periods of inactivity, but what regulates this cycle, and how sensitive it is to the modelling of stellar feedback, remains unclear. We use the MEGATRON high-redshift zoom simulation suite, in which four star-formation and stellar-feedback prescriptions are evolved from identical initial conditions, to study the regulation of stellar mass growth in galaxies with $M_{*} \sim 10^{4} - 10^{8} M_{\odot}$ at $z = 8.5$. We classify galaxies as Star-Forming, Mini-Quenched (no significant star formation over the last 10 Myr), or Quenched (no significant star formation over the last 100 Myr). The feedback prescription controls both how often galaxies are quiescent and how this depends on mass. Models with stronger or more clustered feedback yield larger quiescent fractions compared to the fiducial and Varying IMF models. Duty cycles at fixed mass also differ by factors of several between models. The cold gas profiles of Quenched galaxies are consistent with two physically distinct modes of quenching: mechanical gas evacuation, producing compact, cold gas-poor systems, and thermodynamic suppression, retaining a cold but star-formation-inactive reservoir. At these masses, quiescent galaxies fall below un-lensed JWST/NIRCam detection limits, whereas star-forming galaxies of the same mass do not, and consequently flux-limited samples will be biased towards active phases. Measuring the quiescent fraction as a function of stellar mass in lensing fields would provide a direct test of stellar-feedback models at Cosmic Dawn.
