论文标题
快速旋转磁星II中重力模式的周期间距II。倾斜偶极化石磁场的情况
Period spacings of gravity modes in rapidly rotating magnetic stars II. The case of an oblique dipolar fossil magnetic field
论文作者
论文摘要
语境。恒星内部磁场最近已显示出在重力模式的周期间距模式上留下可检测的签名。 目标。我们研究了旋转轴对旋转轴的混合（螺状和环形）偶极内化石磁场的倾斜的影响对快速旋转恒星中重力模式的频率的影响。 方法。我们使用传统的旋转近似值来计算非磁模式，并对磁场进行扰动处理来计算相应的频移。我们将新的形式主义应用于HD 43317，这是一种磁性，快速旋转的，缓慢脉动的B型恒星，其场的倾斜角约为80°。 结果。我们发现，当磁轴更靠近赤道区域时，在高阶 - 高度重力模式下磁场引起的频率移位较大，而这些模式被捕获。达到90°的倾斜角度达到最大值。所有模式几何形状都观察到了这一趋势。 结论。我们的结果预测，使用重力模式的星空学可以检测到内斜偶极磁场的特征。
Context. Stellar internal magnetic fields have recently been shown to leave a detectable signature on period spacing patterns of gravity modes. Aims. We investigate the effect of the obliquity of a mixed (poloidal and toroidal) dipolar internal fossil magnetic field with respect to the rotation axis on the frequency of gravity modes in rapidly rotating stars. Methods. We use the traditional approximation of rotation to compute non-magnetic modes, and a perturbative treatment of the magnetic field to compute the corresponding frequency shifts. We apply the new formalism to HD 43317, a magnetic, rapidly rotating, slowly pulsating B-type star, whose field has an obliquity angle of about 80°. Results. We find that frequency shifts induced by the magnetic field on high-radial-order gravity modes are larger with increasing obliquity angle, when the magnetic axis is closer to the equatorial region, where these modes are trapped. The maximum value is reached for an obliquity angle of 90°. This trend is observed for all mode geometries. Conclusions. Our results predict that the signature of an internal oblique dipolar magnetic field is detectable using asteroseismology of gravity modes.
