论文标题
在核心和包膜振荡之间耦合引起的迅速旋转伽马型星星的浸入结构的星形遗迹学
Asteroseismology of the dip structure in period-spacings of rapidly rotating gamma Doradus stars caused by the coupling between core and envelope oscillations
论文作者
论文摘要
$ \ it Kepler $太空任务的最新纯种观察表明，在周期间距与迅速旋转$γ$ doradus恒星的时期图中的倾斜结构。在以前的研究中通过数值计算成功地繁殖了浸入结构后，我们在本文中介绍了由于辐射包膜中的引力持续性波与对流核心中的纯惯性波的相互作用而形成的物理机制。我们分析描述了辐射包膜和对流芯中的波解，并在界面上匹配它们以构造本本特莫德。我们从分析中发现了以下几点：DIP结构主要由与界面处的Brunt-Väisälä频率相关的参数控制；随着参数变大，倾角的深度和宽度分别较浅，更大。 lorentzian函数可以近似倾角的形状。倾斜的中心位置的周期等于或略小于对流芯中所涉及的纯惯性模式的周期。我们还根据主要序列恒星的进化模型理解，该参数与对流核边界处的化学成分梯度成反比。因此，浸入结构将提供有关对流芯和辐射包膜之间边界周围边界的不良物理过程的信息，例如扩散，对流过圈和旋转混合。
Recent asteroseismic observations by the $\it Kepler$ space mission have revealed the dip fine structure in the period-spacing versus period diagram of rapidly rotating $γ$ Doradus stars. Following the successful reproduction of the dip structure by numerical calculations in previous studies, we present in this paper the physical mechanism of how the dip is formed as a result of the interaction between the gravito-inertial waves in the radiative envelope and the pure inertial waves in the convective core. We analytically describe the wave solutions in both of the radiative envelope and the convective core, and match them at the interface to construct an eigenmode. We have found from the analysis the following points: the dip structure is mainly controlled by a parameter that has an inverse correlation with Brunt-Väisälä frequency at the interface; the depth and the width of the dip is shallower and larger, respectively, as the parameter gets large; the shape of the dip can be approximated by the Lorentzian function; the period at the central position of the dip is equal to or slightly smaller than that of the involved pure inertial mode in the convective core. We have also understood based on the evolutionary models of main-sequence stars that the parameter is inversely correlated with the chemical composition gradient at the convective-core boundary. The dip structure thus would provide information about the poorly-understood physical processes, such as diffusion, convective overshooting and rotational mixing, around the boundary between the convective core and the radiative envelope.
