论文标题
来自恒星h $α$发射线轮廓的恒星倾斜角度
Stellar Inclination Angles from Be Star H$α$ Emission-Line Profiles
论文作者
论文摘要
我们证明，可以通过H $α$发射线轮廓拟合可靠地确定恒星旋转轴与观察者的视线（通常称为倾斜角度）之间的角度。我们在11个恒星样品上测试我们的方法，并具有来自海军精度光学干涉仪（NPOI）的可用长基线干涉数据。我们适合每个星星的H $α$排放线轮廓，以获得光谱倾斜角$ i _ {\ rmhα} $。然后，我们通过将观察到的干涉可见性与模型可见性拟合，基于天空上的光分布的纯几何表示，我们获得了独立的倾斜角估计，$ i _ {\ rm v^2} $。示例差异，$Δi\ equiv i _ {\ rmhα} - i _ {\ rm v^2} $，正态分布，平均为零，标准偏差为$ 6.7 $度，而线性相关系数在$ i _ {\ rmhα} $和$ i___________________________________________________________m $ r = 0.93 $。由于恒星占所有主要序列B型星的五分之一，因此该H $α$线轮廓拟合技术具有提供有效方法来检测年轻开放式群集中相关的恒星旋转轴的有效方法。此外，如果可以通过极化测量来限制天空平面上的恒星偶然磁盘的方向，则可以确定每个恒星的完整3D恒星旋转向量。
We demonstrate that the angle between star's rotation axis and the observer's line-of-sight, usually called the inclination angle, can be reliably determined for Be stars via H$α$ emission-line profile fitting. We test our method on a sample of 11 Be stars with available long-baseline interferometric data from the Navy Precision Optical Interferometer~(NPOI). We fit the H$α$ emission line profile of each star to obtain a spectroscopic inclination angle $i_{\rm Hα}$. We then obtain an independent inclination angle estimate, $i_{\rm V^2}$, by fitting the observed interferometric visibilities with model visibilities based on a purely geometric representation of the light distribution on the sky. The sample differences, $Δi \equiv i_{\rm Hα} - i_{\rm V^2}$, are normally distributed with a mean of zero and a standard deviation of $6.7$ degrees, and the linear correlation coefficient between $i_{\rm Hα}$ and $i_{\rm V^2}$ is $r=0.93$. As Be stars comprise upwards of one fifth of all main-sequence B-type stars, this H$α$ line profile fitting technique has the potential to provide an efficient method for detecting correlated stellar spin axes in young open clusters. Furthermore, if the orientation of the Be star circumstellar disk on the plane of the sky can be constrained by polarization measurements, it is possible to determine the full 3D stellar rotation vector of each Be star.
