AI 中文总结
本研究基于LEGUS巡天的约8300个星团，利用slug贝叶斯正向建模框架结合c-4神经网络不完备估计器，发现年轻星团人口统计学具有环境依赖性，质量函数斜率普适但高质量截断值环境差异大，星团破坏与质量无关。
AI 中文摘要
星团质量函数与星团寿命均可能随星系环境变化，但测量这种变化颇具挑战，因为观测巡天中星团人口统计学的真实特征始终与星表不完备性相互纠缠。本文利用slug贝叶斯正向建模框架，结合新的基于c-4神经网络的不完备性估计器，分析了来自LEGUS巡天的12个星系中约8300个星团，该方法可将真实星表包含概率直接纳入似然函数，以补偿这些偏差。我们表明该方法能在星系及亚星系尺度上以极高保真度拟合观测到的星团光度函数。研究发现质量函数斜率相对普适，大致符合幂律M⁻²形式，但高质量截断值在星系间及星系内相差数个数量级。拟合结果强烈支持星团破坏与质量无关的模型，但破坏开始的时间仍呈现广泛的环境变化。研究结果证实年轻星团人口统计学具有环境依赖性，最清晰的信号出现在星团质量函数的高端，但这些变化无法用现有文献中的任何模型很好解释，也不与单位面积恒星形成率或剪切强度等性质直接相关。
英文摘要
Both the star cluster mass function and the lifetimes of clusters may vary with galactic environment, but measuring this variation is challenging because in observational surveys real features of cluster demographics are invariably entangled with catalogue incompleteness. Here we analyse $\approx$ 8300 star clusters in 12 galaxies drawn from the LEGUS survey using the slug Bayesian forward modelling framework coupled to our new c-4 neural network-based completeness estimator, which allows us to incorporate realistic catalogue-inclusion probabilities directly into the likelihood and compensate for these biases. We show that this approach allows us to fit observed cluster luminosity functions with excellent fidelity at both galactic and sub-galactic scales. We find that mass function slopes are relatively universal and broadly consistent with a power law $M^{-2}$ form, but high mass truncations vary by orders of magnitude both between and within galaxies. Our fits also strongly favour models where cluster disruption is mass-independent, but the time at which disruption begins again shows wide environmental variations. Our results demonstrate that young cluster demographics are environmentally dependent, with the clearest signal appearing at the upper end of the cluster mass function, but that these variations are not well-explained by any of the models currently in the literature, and do not correlate straightforwardly with properties such as star formation rate per unit area or strength of shear.
