Modelling neutron star mountains
Modelling neutron star mountains
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DOI：
10.1093/mnras/staa3635
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发表时间：
2020-09
影响因子：
4.8
通讯作者：
F. Gittins;N. Andersson;David A. Jones
中科院分区：
文献类型：
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作者：
F. Gittins;N. Andersson;David A. Jones
随着引力波天文学时代的真正开始，来自旋转中子星的引力辐射仍然难以捉摸。快速旋转的中子星是连续波搜索的主要目标，因为根据广义相对论，只要它们不对称变形，它们就会发射引力波。人们相信，探测到这种辐射将解开为什么没有观测到脉冲星旋转接近分裂频率的答案。我们回顾了现有的关于中子星地壳可以支持的最大山的研究，批评了关键假设，并确定了需要解决的与边界条件有关的问题。在此基础上，我们提出了一种新的中子星山模拟方案。这个方案的关键要素是对使恒星远离球形的基准力的描述。我们考虑三个例子：一个源势，它是拉普拉斯方程的解，另一个解，它不在恒星的核心中起作用，还有一个热压扰动。在所有的情况下，我们发现最大的四极柱比以前估计的最大山峰大小要小几个到两个数量级。
As the era of gravitational-wave astronomy has well and truly begun, gravitational radiation from rotating neutron stars remains elusive. Rapidly spinning neutron stars are the main targets for continuous-wave searches since, according to general relativity, provided they are asymmetrically deformed, they will emit gravitational waves. It is believed that detecting such radiation will unlock the answer to why no pulsars have been observed to spin close to the break-up frequency. We review existing studies on the maximum mountain that a neutron star crust can support, critique the key assumptions and identify issues relating to boundary conditions that need to be resolved. In light of this discussion, we present a new scheme for modelling neutron star mountains. The crucial ingredient for this scheme is a description of the fiducial force which takes the star away from sphericity. We consider three examples: a source potential which is a solution to Laplace’s equation, another solution which does not act in the core of the star and a thermal pressure perturbation. For all the cases, we find that the largest quadrupoles are between a factor of a few to two orders of magnitude below previous estimates of the maximum-mountain size.