arXiv:2412.12244astro-ph.SRastro-ph.GA2024-12被引 7

基于8000颗恒星数据,用新模型精准估算恒星年龄。

ChronoFlow: A Data-Driven Model for Gyrochronology

  • 构建大型恒星旋转数据集,开发可灵活拟合旋转演化的新模型。
  • 集群年龄误差仅0.08 dex(约15%),单星年龄误差0.7 dex。
  • 适合研究恒星演化、星团年龄及独立恒星年龄推断的学者。

陀螺年代学是一种利用恒星自转周期约束其年龄的技术,因磁制动导致主序星自转速率随时间变化。该方法对主序型FGKM恒星尤为有效,而传统方法精度不足。为准确刻画自转速率的观测离散性,我们构建了迄今最大标准化的开放星团旋转星表,包含约8000颗恒星,覆盖1.5百万年至40亿年间的30个星团/星协。我们提出ChronoFlow:一种灵活的数据驱动模型,能精确捕捉观测到的旋转离散性。结果表明,ChronoFlow可准确前向模拟旋转演化,并推断星团与单颗恒星的年龄。集群年龄统计不确定度为0.06 dex(约15%),单星年龄为0.7 dex。通过系统测试验证了消光模型、成员认定和校准年龄的影响,额外引入0.06 dex不确定性,总误差预算为0.08 dex。将ChronoFlow应用于M34、NGC 2516、NGC 6709及Theia 456星流,结果表明其可高精度估计共时星群年龄,并约束单星年龄。其预测还可用于改进物理自转衰减模型。ChronoFlow已开源于https://github.com/philvanlane/chronoflow。

原文摘要 · Abstract (English)

Gyrochronology is a technique for constraining stellar ages using rotation periods, which change over a star's main sequence lifetime due to magnetic braking. This technique shows promise for main sequence FGKM stars, where other methods are imprecise. However, the observed dispersion in rotation rates for similar coeval stars has historically been difficult to characterize. To properly understand this complexity, we have assembled the largest standardized data catalog of rotators in open clusters to date, consisting of $\approx$8,000 stars across 30 open clusters/associations spanning ages of 1.5 Myr to 4 Gyr. We have also developed ChronoFlow: a flexible data-driven model which accurately captures observed rotational dispersion. We show that ChronoFlow can be used to accurately forward model rotational evolution, and to infer both cluster and individual stellar ages. We recover cluster ages with a statistical uncertainty of 0.06 dex ($\approx$15%), and individual stellar ages with a statistical uncertainty of 0.7 dex. Additionally, we conducted robust systematic tests to analyze the impact of extinction models, cluster membership, and calibration ages. These contribute an additional 0.06 dex of uncertainty in cluster age estimates, resulting in a total error budget of 0.08 dex. We apply ChronoFlow to estimate ages for M34, NGC 2516, NGC 6709, and the Theia 456 stellar stream. Our results show that ChronoFlow can precisely estimate the ages of coeval stellar populations, and constrain ages for individual stars. Furthermore, its predictions may be used to inform physical spin down models. ChronoFlow is publicly available at https://github.com/philvanlane/chronoflow.

恒星年龄陀螺年代学数据驱动星团

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