Recent photometric observations of massive stars show ubiquitous low-frequency ‘red noise’ variability, which has been interpreted as internal gravity waves (IGWs). Simulations of IGWs generated by convection show smooth surface wave spectra, qualitatively matching the observed red noise. Theoretical calculations using linear wave theory by Shiode et al. and Lecoanet et al. predict IGWs should manifest at the surface as regularly spaced peaks associated with standing g modes. In light of the apparent discrepancy between these theories and simulations/observations, we test the theories with simplified 2D numerical simulations of wave generation by convection. The simulations agree with the transfer function calculations presented in Lecoanet et al., demonstrating that the transfer function correctly models linear wave propagation. However, there are differences between our simulations and the g-mode amplitude predictions of Shiode et al. This is because that work did not take into account the finite width of the g-mode peaks; after correcting for this finite width, we again find good agreement between theory and simulations. This paper verifies the theoretical approach of Lecoanet et al. and strengthens their conclusion that IGWs generated by core convection do not have a surface manifestation consistent with observed low-frequency variability of massive stars.

中文翻译：

---

随机激发的内部重力波的表面表现

最近对大质量恒星的光度观测显示普遍存在的低频“红噪声”变化，这被解释为内部重力波（IGW）。对流产生的 IGW 的模拟显示平滑的表面波光谱，与观察到的红噪声定性匹配。Shiode 等人使用线性波理论的理论计算。和 Lecoanet 等人。预测 IGW 应该在表面表现为与站立 g 模式相关的规则间隔的峰。鉴于这些理论与模拟/观察之间的明显差异，我们通过对流产生波的简化二维数值模拟来测试这些理论。模拟与 Lecoanet 等人提出的传递函数计算一致，表明传递函数正确地模拟了线性波传播。然而，我们的模拟与 Shiode 等人的 g 模式幅度预测之间存在差异。这是因为该工作没有考虑 g 模式峰的有限宽度；在校正了这个有限宽度之后，我们再次发现理论和模拟之间有很好的一致性。本文验证了 Lecoanet 等人的理论方法。并加强了他们的结论，即核心对流产生的 IGW 不具有与观察到的大质量恒星的低频变化一致的表面表现。本文验证了 Lecoanet 等人的理论方法。并加强了他们的结论，即核心对流产生的 IGW 不具有与观察到的大质量恒星的低频变化一致的表面表现。本文验证了 Lecoanet 等人的理论方法。并加强了他们的结论，即核心对流产生的 IGW 不具有与观察到的大质量恒星的低频变化一致的表面表现。