[论文解读] The THESAN-ZOOM project: Burst, quench, repeat -- unveiling the evolution of high-redshift galaxies along the star-forming main sequence

William McClymont, Sandro Tacchella+11 more|arXiv (Cornell University)|Feb 28, 2025

Astronomy and Astrophysical Research被引用 14

一句话总结

本论文介绍了 THESAN-ZOOM 项目，旨在研究高红移星系在沿着恒星形成主序演化时的爆发、淬火和重复循环。

ABSTRACT

Characterizing the evolution of the star-forming main sequence (SFMS) at high redshift is crucial to contextualize the observed extreme properties of galaxies in the early Universe. We present an analysis of the SFMS and its scatter in the THESAN-ZOOM simulations, where we find a redshift evolution of the SFMS normalization scaling as $\propto (1+z)^{2.64\pm0.03}$, significantly stronger than is typically inferred from observations. We can reproduce the flatter observed evolution by filtering out weakly star-forming galaxies, implying that current observational fits are biased due to a missing population of lulling galaxies or overestimated star-formation rates. We also explore star-formation variability using the scatter of galaxies around the SFMS ($σ_{\mathrm{MS}}$). At the population level, the scatter around the SFMS increases with cosmic time, driven by the increased importance of long-term environmental effects in regulating star formation at later times. To study short-term star-formation variability, or ''burstiness'', we isolate the scatter on timescales shorter than 50 Myr. The short-term scatter is larger at higher redshift, indicating that star formation is indeed more bursty in the early Universe. We identify two starburst modes: (i) externally driven, where rapid large-scale inflows trigger and fuel prolonged, extreme star formation episodes, and (ii) internally driven, where cyclical ejection and re-accretion of the interstellar medium in low-mass galaxies drive bursts, even under relatively steady large-scale inflow. Both modes occur at all redshifts, but the increased burstiness of galaxies at higher redshift is due to the increasing prevalence of the more extreme external mode of star formation.

研究动机与目标

• 激发沿着恒星形成主序的高红移星系演化的研究。
• 将 THESAN-ZOOM 项目介绍为一系列模拟/分析，用以研究爆发与淬火事件。
• 分析爆发、淬火与再点燃事件如何塑造早期星系的恒星形成史。

提出的方法

• 呈现和/或利用 THESAN-ZOOM 仿真框架。
• 研究高红移星系的恒星形成史和主序演化。
• 将模拟结果与早期星系群体的观测约束进行比较。

实验结果

研究问题

• RQ1 爆发与淬火事件如何影响高红移恒星形成主序上星系的位置及其演化？
• RQ2 早期宇宙中爆发/淬火循环的占空比与再现性是多少？
• RQ3 反馈和其他物理过程如何驱动高红移星系在主序中的演化？

主要发现

• 在所提供的摘录中不可用。