标题： 缓慢脉动B型星重力模态中的非线性共振检测：五种迭代去白策略的结果 显示英文标题

标题： Detection of nonlinear resonances among gravity modes of slowly pulsating B stars: results from five iterative prewhitening strategies

摘要： 上下文。 缓慢脉动B（SPB）恒星是主序多周期振荡器，它们表现出非径向重力模式。 对于这些脉动恒星中的一部分，通过开普勒空间望远镜获得的4年光度光曲线揭示了周期间距模式，从中可以推断其内部旋转和混合情况。 到目前为止，在这种推断中通常忽略了任何直接的共振模式耦合。 目标。 我们重新分析了一组38颗已知的开普勒SPB恒星的光曲线。 其中26颗恒星的内部结构，包括旋转和混合，最近是通过它们的偶极前向振荡模式推断出来的。 我们的目标是检测最大振幅重力模式之间的直接非线性共振模式耦合。 方法。 我们使用基于线性和非线性回归的五种不同的迭代去噪策略，从每颗恒星中提取多达200个周期信号。 然后通过验证它们是否满足共振相位关系来识别可能的耦合重力模式。 结果。 在38颗SPB恒星中，有32颗我们发现至少有一个候选共振，该共振在光曲线的线性模型和最佳非线性回归模型拟合中都能被检测到，并且涉及两个最大振幅模式中的至少一个。 结论。 大多数开普勒SPB恒星基于最大振幅模式显示出直接的非线性共振。 因此，这些恒星是进行中等质量矮星非线性星震学建模的理想目标，以评估模式耦合在探测其内部物理中的重要性。 显示英文摘要

摘要： Context. Slowly pulsating B (SPB) stars are main-sequence multi-periodic oscillators that display non-radial gravity modes. For a fraction of these pulsators, 4-year photometric light curves obtained with the Kepler space telescope reveal period spacing patterns from which their internal rotation and mixing can be inferred. In this inference, any direct resonant mode coupling has usually been ignored so far. Aims. We re-analysed the light curves of a sample of 38 known Kepler SPB stars. For 26 of those, the internal structure, including rotation and mixing, was recently inferred from their dipole prograde oscillation modes. Our aim is to detect direct nonlinear resonant mode coupling among the largest-amplitude gravity modes. Methods. We extract up to 200 periodic signals per star with five different iterative prewhitening strategies based on linear and nonlinear regression applied to the light curves. We then identify candidate coupled gravity modes by verifying whether they fulfil resonant phase relations. Results. For 32 of 38 SPB stars we find at least 1 candidate resonance that is detected in both the linear and the best nonlinear regression model fit to the light curve and involves at least one of the two largest-amplitude modes. Conclusions. The majority of the Kepler SPB stars reveal direct nonlinear resonances based on the largest-amplitude modes. These stars are thus prime targets for nonlinear asteroseismic modelling of intermediate-mass dwarfs to assess the importance of mode couplings in probing their internal physics.