标题： 应对恒星物理中的不确定性：利用食双星校准对流超射 显示英文标题

标题： Confronting uncertainties in stellar physics: calibrating convective overshooting with eclipsing binaries

摘要： 作为一项更大计划的一部分，旨在更好地量化恒星计算中的不确定性，我们尝试通过食双星系统校准低到中等质量恒星对流超射的程度。 我们使用详细的双星恒星演化代码STARS对12个这样的系统进行建模，这些系统的组分质量在1.3至6.2个太阳质量之间，生成了金属丰度和超射参数的模型网格。 从这些模型中，我们确定了每个系统的最佳拟合参数。 对于三个系统，我们的模型均无法产生令人满意的拟合。 对于其余的系统，没有单一的对流超射参数能够适配所有系统，但大多数系统可以用0.09至0.15之间的超射参数很好地描述，这相当于核心上方混合区域扩展约0.1-0.3个压力尺度高度。 在九个系统中，我们能够获得良好拟合，其中七个系统可以用一个0.15的参数合理地拟合。 我们没有发现超射程度与质量或金属丰度之间存在趋势的证据，尽管数据集规模有限。 我们使用第二个演化代码MESA重复了计算，发现两种代码之间总体上是一致的。 MESA模型所需的混合区域在对流核心上方的扩展约为0.15-0.4个压力尺度高度。 对于系统EI Cep，我们发现MESA给出的超射区域比STARS的大约0.1个压力尺度高度，而对于次级星，差异仅为0.05个压力尺度高度。 显示英文摘要

摘要： As part of a larger program aimed at better quantifying the uncertainties in stellar computations, we attempt to calibrate the extent of convective overshooting in low to intermediate mass stars by means of eclipsing binary systems. We model 12 such systems, with component masses between 1.3 and 6.2 solar masses, using the detailed binary stellar evolution code STARS, producing grids of models in both metallicity and overshooting parameter. From these, we determine the best fit parameters for each of our systems. For three systems, none of our models produce a satisfactory fit. For the remaining systems, no single value for the convective overshooting parameter fits all the systems, but most of our systems can be well described with an overshooting parameter between 0.09 and 0.15, corresponding to an extension of the mixed region above the core of about 0.1-0.3 pressure scale heights. Of the nine systems where we are able to obtain a good fit, seven can be reasonably well fit with a single parameter of 0.15. We find no evidence for a trend of the extent of overshooting with either mass or metallicity, though the data set is of limited size. We repeat our calculations with a second evolution code, MESA, and we find general agreement between the two codes. For the extension of the mixed region above the convective core required by the MESA models is about 0.15-0.4 pressure scale heights. For the system EI Cep, we find that MESA gives an overshooting region that is larger than the STARS one by about 0.1 pressure scale heights for the primary, while for the secondary the difference is only 0.05 pressure scale heights.