论文标题
调查不透明度修改和反应速率不确定性以解决头孢虫质量差异
Investigating Opacity Modifications and Reaction Rate Uncertainties to Resolve the Cepheid Mass Discrepancy
论文作者
论文摘要
源自脉动或二进制动力学的头虫质量通常低于从恒星进化模型中得出的质量。最近的努力致力于调查丰度，质量损失，旋转，对流和过度施加处方的影响，以修改进化轨道，以减少或消除这种头孢虫的质量差异。尽管这些方法是有希望的，无论是单独还是组合，都需要更多的工作来区分可能的解决方案。在这里，我们研究了使用MESA代码对头孢虫进化的核反应率和不透明度修改。我们讨论了提议解释杂交主序列βCEP/缓慢脉动B（SPB）变量的脉动化特性的200,000-400,000 K的包膜温度下不透明度增加的效果，这些脉动特性将演变成头孢虫。我们利用MESA中的RSP非线性径向脉动建模能力来计算Galactic Cepheids V1334 CYG，Polaris和Delta Cep的周期和径向速度幅度。
Cepheid masses derived from pulsations or binary dynamics are generally lower than those derived from stellar evolution models. Recent efforts have been dedicated to investigating the effects of abundances, mass loss, rotation, convection and overshooting prescriptions for modifying the evolution tracks to reduce or remove this Cepheid mass discrepancy. While these approaches are promising, either alone or in combination, more work is required to distinguish between possible solutions. Here we investigate nuclear reaction rate and opacity modifications on Cepheid evolution using the MESA code. We discuss the effects of opacity increases at envelope temperatures of 200,000-400,000 K proposed to explain the pulsation properties of hybrid main-sequence beta Cep/Slowly Pulsating B (SPB) variables which will evolve into Cepheids. We make use of the RSP nonlinear radial pulsation modeling capability in MESA to calculate periods and radial velocity amplitudes of Galactic Cepheids V1334 Cyg, Polaris, and delta Cep.
