A possible origin of kilohertz quasi-periodic oscillations (QPOs) in low-mass X-ray binaries is proposed. Recent numerical magnetohydrodynamic simulations of accretion disks with turbulent magnetic fields of magneto-rotational instability definitely show the presence of two-armed spiral structure in the quasi-steady state of accretion disks. In such deformed disks, two-armed (⁠|$m=2$|⁠) c-mode (⁠|$n=1$|⁠) oscillations are excited by wave–wave resonant instability. Among these excited oscillations, the fundamental in the radial direction (⁠|$n_{\rm r}=0$|⁠) will be the higher kHz QPO of twin QPOs, and the first overtone (⁠|$n_{\rm r}=1$|⁠) in the radial direction will be the lower kHz QPO of the twin. A possible cause of the twin high-frequency QPOs in black hole X-ray binaries is also discussed in the final section.

中文翻译：

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低质量X射线双星中千赫兹准周期振荡的可能起源

提出了低质量X射线双星中千赫兹准周期振荡（QPO）的可能起源。具有磁旋转不稳定性的湍流磁场的吸积盘的最新数值磁流体动力学模拟无疑表明，在吸积盘的准稳态下存在两臂螺旋结构。在这种变形的磁盘中，两臂（⁠| $ m = 2 $ |⁠）c模式（⁠| $ n = 1 $ |⁠）的振动是由波-波共振不稳定性激发的。在这些激发振荡中，径向基波（⁠| $ n _ {\ rm r} = 0 $ |⁠）将是两个QPO的较高kHz QPO，以及第一个泛音（⁠| $ n _ {\ rm r } = 1 $ |⁠）在径向方向上将是孪晶的较低kHz QPO。最后一节还将讨论黑洞X射线二进制文件中双高频QPO的可能原因。