发表机构
Lanzhou Center for Theoretical Physics, Key Laboratory of Theoretical Physics of Gansu Province, Key Laboratory of Quantum Theory and Applications of MoE, Gansu Provincial Research Center for Basic Disciplines of Quantum Physics, Lanzhou 730000, China; Institute of Theoretical Physics & Research Center of Gravitation, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China; Department of Astronomy, School of Physics, Peking University, Beijing 100871, China; Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China; National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, China（兰州理论物理中心，甘肃省理论物理重点实验室，教育部量子理论与应用重点实验室，甘肃省量子物理基础学科研究中心; 兰州大学物理科学与技术学院理论物理与引力研究中心; 北京大学物理学院天文学系; 北京大学科维理天文与天体物理研究所; 中国科学院国家天文台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究探讨超亮X射线脉冲星中磁致热弹性山脉产生的连续引力波，发现强磁场下非线性热传输增强四极矩，快速旋转的银河系ULXPs可能成为下一代探测器的目标。
AI 中文摘要
快速旋转、非轴对称变形的中子星（NS）是当前及下一代地面探测器进行连续引力波（CGW）搜索的有前景目标。超亮X射线脉冲星（ULXPs）以超爱丁顿吸积和强磁场为特征，提供了可能发展出显著非轴对称变形的极端环境。在本信中，我们研究了ULXPs吸积壳层中由磁致温度不对称性产生的热弹性山脉。我们将壳层热结构与吸积柱模型联系起来，并求解完整的各向异性热传输方程，将先前的微扰处理方法扩展到非线性、强磁化区域。我们发现，弱场近似在$B_{\rm ref}\sim10^{13}\\,{\rm G}$附近开始失效，超过该值后，非线性各向异性热传输显著改变了四极热响应。由此产生的热不对称性在更高场强下产生了显著的热弹性质量四极矩。尽管目前已知的ULXPs因其相对较慢的自转和在多数情况下较大的距离而不利于作为CGW目标，但我们示例性的自转演化计算表明，中子星可以以约$20\\,{\rm ms}$的自转周期进入超爱丁顿吸积相。这种快速旋转的银河系ULXPs可能位于下一代探测器（如爱因斯坦望远镜和宇宙探测器）的预期灵敏度范围内。这些结果将热山脉物理扩展到与ULXPs相关的强磁化区域，并将超爱丁顿吸积与未来的CGW观测联系起来。
英文摘要
Fast-spinning, nonaxisymmetrically deformed neutron stars (NSs) are promising targets for continuous gravitational-wave (CGW) searches with current and next-generation ground-based detectors. Ultraluminous X-ray pulsars (ULXPs), characterized by super-Eddington accretion and strong magnetic fields, provide extreme environments in which substantial nonaxisymmetric deformations may develop. In this Letter, we investigate thermo-elastic mountains generated by magnetically induced temperature asymmetries in the accreted crusts of ULXPs. We connect the crustal thermal structure to an accretion-column model and solve the full anisotropic heat-transport equation, extending previous perturbative treatments into the nonlinear, strongly magnetized regime. We find that the weak-field approximation begins to break down near $B_{\rm ref}\sim10^{13}\,{\rm G}$, beyond which nonlinear anisotropic heat transport significantly modifies the quadrupolar thermal response. The resulting thermal asymmetries generate substantial thermo-elastic mass quadrupoles at higher field strengths. Although the currently known ULXPs are unfavorable CGW targets because of their relatively slow spins and, in most cases, large distances, our illustrative spin-evolution calculations show that a NS can enter the super-Eddington accretor phase with a spin period of order $20\,{\rm ms}$. Such rapidly rotating Galactic ULXPs could lie within the projected sensitivities of next-generation detectors such as the Einstein Telescope and Cosmic Explorer. These results extend thermal-mountain physics into the strongly magnetized regime relevant to ULXPs and connect super-Eddington accretion with prospective CGW observations.
Comments7 pages, 3 figures, and Supplemental Material
