标题： 关于类似太阳振荡的光谱图解释。 离心畸变的影响 显示英文标题

标题： On the interpretation of echelle diagrams for solar-like oscillations. Effect of centrifugal distortion

摘要： 本研究旨在确定缓慢到中等旋转对太阳型振荡光谱中经常存在的规则模式的影响。 我们专注于众所周知的恒星振荡诊断工具——echelle图，探讨旋转如何可能修改大间距和小间距的估计值，以及模式识别。 我们通过一个实际案例来说明这项工作：太阳型恒星$\eta$Bootis。 建模时考虑了旋转对平衡模型的影响（通过有效重力）以及对振荡频率的影响（通过摄动和非摄动计算）。 我们将这两种类型计算的结果在规则间距（如小间距和尺度化的小间距）和echelle图的背景下进行了比较。 我们表明，对于echelle图，摄动方法在旋转速度高达40-50公里/秒的情况下仍然有效。 我们还表明，对于太阳型恒星测量的旋转速度，理论振荡频率必须在旋转率的二阶项中进行校正，包括近简并效应。 对于约16公里/秒及以上的旋转速度，通过echelle图的大间距和模式识别诊断可能会因旋转分裂模式的$m\neq0$成分的存在而发生显著变化。 我们发现这些效应可以在观测频率范围内被检测到。 对小间距和尺度化小间距的旋转影响分析显示，这些效应可以达到甚至超过表面效应（如湍流、微观扩散等）的量级。 此外，我们表明，即使对于小的恒星旋转速度（从10-15公里/秒），尺度化间距也会受到恒星变形的显著影响，因此在将其用作探测深层恒星内部的指标时需要谨慎。 显示英文摘要

摘要： This work aims at determining the impact of slow to moderate rotation on the regular patterns often present in solar-like oscillation spectra. We focus on the well-known asteroseismic diagnostic echelle diagrams, examining how rotation may modify the estimates of the large and small spacings, as well as the identification of modes. We illustrate the work with a real case: the solar-like star $\eta$ Bootis. The modeling takes into account rotation effects on the equilibrium models through an effective gravity and on the oscillation frequencies through both perturbative and non-perturbative calculations. We compare the results of both type of calculations in the context of the regular spacings (like the small spacings and the scaled small spacings) and echelle diagrams. We show that for echelle diagrams the perturbative approach remains valid for rotational velocities up to 40-50 km/s. We show that for the rotational velocities measured in solar-like stars, theoretical oscillation frequencies must be corrected up to the second-order in terms of rotation rate, including near degeneracy effects. For rotational velocities of about 16 km/S and higher, diagnostics on large spacings and on modal identification through echelle diagrams can be significantly altered by the presence of the $m\neq0$ components of the rotationally split modes. We found these effects to be detectable in the observed frequency range. Analysis of the effects of rotation on small spacings and scaled small spacings reveals that these can be of the order of, or even larger than surface effects, typically turbulence, microscopic diffusion, etc. Furthermore, we show that scaled spacings are significantly affected by stellar distortion even for small stellar rotational velocities (from 10-15 km/s) and therefore some care must be taken when using them as indicators for probing deep stellar interiors.