AI 中文总结
研究FIRE-2项目模拟星系中恒星形成的遍历性，通过与恒星形成主序列偏差及总体平均与时间平均匹配情况来考量，发现偏差随时间趋近遍历性行为，不同时间尺度估计器有差异，结果需结合样本进一步研究。
AI 中文摘要
我们研究了来自FIRE-2（现实环境中的反馈）项目的模拟星系中恒星形成的遍历性。我们将遍历性的考量限制在与偏离恒星形成主序列（SFMS）相关的方面，进而基于模拟的可观测属性，研究总体平均是否与时间平均的恒星形成历史（SFHs）相匹配。我们发现在这些高分辨率模拟中，随着时间推移，单个星系与SFMS的偏差倾向于趋近遍历性行为，无论采用何种SFMS定义和恒星形成估计器。即便考虑由Sérsic指数追踪的星系形态，这一趋势依然存在，尽管球状主导形态的SFMS偏差范围比盘状主导形态小。不出所料，基于较短时间尺度（$10^{7}$年）的恒星形成估计器比基于较长时间尺度（$10^{9}$年）的估计器更快趋近遍历性行为。我们提醒这些发现应结合当前样本情况来考虑，并且应进一步研究，特别是高红移演化和活跃星系核的影响。
英文摘要
We investigate the ergodicity of star formation in simulated galaxies from the FIRE-2 (Feedback In Realistic Environments) project. We restrict ergodicity considerations to being related to deviations from the star-forming main sequence (SFMS), and in turn whether ensemble averages across populations match time-averaged star formation histories (SFHs) based on simulated observable properties. We find that in these high-resolution simulations the deviations of individual galaxies from the SFMS tend to approach ergodic behavior over time, regardless of the SFMS definition adopted and the star formation estimator used. This trend persists when galaxy morphology, as traced by Sérsic index, is considered despite the spheroid-dominated morphologies showing a smaller range of SFMS deviations than the disk-dominated morphologies. Unsurprisingly, we find more rapid convergence to ergodic behavior for star formation estimators based on shorter time scales ($10^{7}$ years) as opposed to longer ($10^{9}$ years). We caution that these findings should be considered in the context of the current sample and that further studies, particularly of high redshift evolution and the impact of active galactic nuclei should be investigated.
Comments17 pages, 11 figures, 2 tables. Published in ApJ
Journal refAstrophys. J. 1006 (2026) 98
