探测恒星内部磁场：包含自转与磁场的二维振荡框架
Probing magnetic fields in stars: A 2D oscillation framework including rotation and magnetism
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中文总结 AI 辅助
本研究实现了纳入自转与磁场效应的二维振荡代码新实现，验证了其可靠性，发现内部磁场会在γ Dor恒星的g模式周期间隔留下特征，为探测恒星深层磁场提供了星震诊断手段。
中文摘要 AI 辅助
理解恒星内部磁场的作用仍是描述角动量传输与恒星演化的重大挑战，因此探测恒星内部磁场至关重要，而星震学为此提供了有力手段。本研究中，我们实现了二维振荡代码Adaptive Code of Oscillations towards Realistic modeling的新版本，该版本纳入了恒星自转与磁场的双重效应。此代码已实现模块化，可通过符号计算方法指定需求解的方程组及相关假设；我们采用谱方法求解模式的角向部分，用高阶有限差分法求解径向部分，以完整求解绝热非径向脉动方程组。作为第一步，我们聚焦于沿恒星自转轴的纯环向轴对称磁场，将数值结果与弱场 regime下的一阶微扰预测、强磁场情形下的自转与磁场传统近似（TARM）进行对比，验证了该代码新实现与微扰法、TARM方法吻合良好，证明了代码的鲁棒性，同时明确了这些方法的适用范围。我们发现内部磁场会在g模式的周期间隔中留下特征信号，这些特征为探测γ Dor恒星的深层恒星磁场提供了极具潜力的星震诊断方法。未来工作将致力于将该框架扩展至更真实的磁场拓扑结构及更广泛的脉动恒星，包括红巨星。
英文摘要
Understanding the role of internal magnetic fields in stars remains a major challenge for the description of angular momentum transport and stellar evolution. It is therefore essential to probe these magnetic fields within the star, and asteroseismology provides a powerful means to do so. In this work, we present a new implementation of the 2D oscillation code ( ), which incorporates the effects of both stellar rotation and magnetic fields. Adaptive Code of Oscillations towards Realistic modeling The code has been rendered modular, making it possible to specify the set of equations to solve and the assumptions through a symbolic calculus approach. The full set of adiabatic, non-radial pulsation equations is solved using a spectral approach for the angular part of the modes and high-order finite differences for the radial part. As a first step, we focus on a magnetic field that is purely toroidal and axisymmetric about the star's rotation axis. The numerical results are compared against first-order perturbative predictions in the weak-field regime and with the traditional approximation of rotation and magnetism (TARM) in the case of stronger magnetic fields. We validate this new implementation of against perturbative and TARM approaches, showing good agreement and demonstrating the robustness of the code. The breakdown of these methods provides general validity limits. We show that internal magnetic fields leave signatures in the period spacing of g modes. These features provide a promising seismic diagnostic to probe deep stellar magnetism in γ Dor stars. Future work will aim to extend this framework to more realistic magnetic field topologies and a broader range of pulsating stars, including red giants.
