论文标题
质量亮度平面的恒星年龄确定
Stellar age determination in the Mass-Luminosity Plane
论文作者
论文摘要
恒星的年龄在历史上依赖于标准化模型网格的等异连拟合。尽管这些恒星模型对巨大恒星的观察样品提供了关键限制，但它们继承了许多系统的不确定性，主要是在整个网格中应用的内部混合机制中，从根本上破坏了等速线方法。在这项工作中，我们利用Higgins＆Vink的M-L平面来确定出色的年龄，而经过混合校正的模型应用了校准的核心过冲的Alpha_ov和旋转速率，以适合观察数据。我们提供多个测试床来展示我们的新方法，同时还提供了与常用的同句方法的比较，突出了主要的系统错误。我们重现了单个O恒星的演变，并分析了VLT-Flames Tarantula调查中O和B超级巨人的更广泛样本，从而为Alpha_ov，Omega/Omega_crit估算的专用模型提供了专用模型，并最终使人年龄。 M-L平面突出了O超级样本的光谱质量中的巨大差异。此外，M-L平面还表明，B超巨人样品的进化质量是不合适的。最后，我们利用了脱落的二进制文件，VFTS 642和VFTS 500，并呈现出其年龄，这是由于其精确的动力学质量而产生的，提供了限制其内部混合的机会。对于近TAMS系统，VFTS 500，我们发现两个组件都需要大量的核心过冲（Alpha_ov〜0.5），这意味着延长的主序宽度。因此，我们推断出绝大多数B超级巨人仍在其内核中燃烧氢。
The ages of stars have historically relied on isochrone fitting of standardised grids of models. While these stellar models have provided key constraints on observational samples of massive stars, they inherit many systematic uncertainties, mainly in the internal mixing mechanisms applied throughout the grid, fundamentally undermining the isochrone method. In this work, we utilise the M-L plane of Higgins & Vink as a method of determining stellar age, with mixing-corrected models applying a calibrated core overshooting alpha_ov and rotation rate to fit the observational data. We provide multiple test-beds to showcase our new method, while also providing comparisons to the commonly-used isochrone method, highlighting the dominant systematic errors. We reproduce the evolution of individual O stars, and analyse the wider sample of O and B supergiants from the VLT-FLAMES Tarantula Survey, providing dedicated models with estimates for alpha_ov, Omega/Omega_crit, and ultimately stellar ages. The M-L plane highlights a large discrepancy in the spectroscopic masses of the O supergiant sample. Furthermore the M-L plane also demonstrates that the evolutionary masses of the B supergiant sample are inappropriate. Finally, we utilise detached eclipsing binaries, VFTS 642 and VFTS 500, and present their ages resulting from their precise dynamical masses, offering an opportunity to constrain their interior mixing. For the near-TAMS system, VFTS 500, we find that both components require a large amount of core overshooting (alpha_ov ~ 0.5), implying an extended main-sequence width. We hence infer that the vast majority of B supergiants are still burning hydrogen in their cores.
