Eclipses of continuous gravitational waves as a probe of stellar structure
Eclipses of continuous gravitational waves as a probe of stellar structure
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DOI：
10.1103/physrevd.101.024039
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发表时间：
2019-12
影响因子：
5
通讯作者：
P. Marchant;K. Breivik;C. Berry;I. Mandel;S. Larson
中科院分区：
文献类型：
--
作者：
P. Marchant;K. Breivik;C. Berry;I. Mandel;S. Larson
虽然引力波与物质的相互作用很弱，但它们的传播受到引力势的影响。如果引力波源被一颗星星遮蔽，测量这些扰动提供了一种直接测量整个恒星内部质量分布的方法。我们计算预期的夏皮罗时间延迟，放大，并在日食偏转，并显示如何可以用来推断食体的质量分布。我们确定了来自中子星的连续引力波作为检测这种效应的最佳候选者。当太阳遮蔽一个遥远的源时，根据日食的深度，时间延迟可以变化高达$\ensuremath{\sim}0.034\text{}\mathrm{ms}$，引力波应变振幅可以增加$\ensuremath{\sim} 4%$，源在天空中的视位置可以变化${4}^{\ensuremath {\sim}\ensuremath {\sim} 4%$。吸积中子星与充满罗氏瓣的伴星有很高的概率表现出日食，产生类似的时间延迟，但在振幅和天空位置的变化无法检测。即使对于旋转最快的中子星，这个时间延迟也只相当于引力波相位的百分之几，这使得它成为一个极具挑战性的测量。然而，如果连续引力波的来源存在于当前天文台的探测极限之下，下一代仪器将能够以足够的精度观测它们，以测量食星星的信号。探测这种效应将提供一种新的直接探测恒星内部的方法，补充星震学和太阳中微子探测。
Although gravitational waves only interact weakly with matter, their propagation is affected by a gravitational potential. If a gravitational wave source is eclipsed by a star, measuring these perturbations provides a way to directly measure the distribution of mass throughout the stellar interior. We compute the expected Shapiro time delay, amplification, and deflection during an eclipse, and show how this can be used to infer the mass distribution of the eclipsing body. We identify continuous gravitational waves from neutron stars as the best candidates to detect this effect. When the Sun eclipses a far-away source, depending on the depth of the eclipse the time delay can change by up to $\ensuremath{\sim}0.034\text{ }\text{ }\mathrm{ms}$, the gravitational-wave strain amplitude can increase by $\ensuremath{\sim}4%$, and the apparent position of the source in the sky can vary by ${4}^{\ensuremath{'}\ensuremath{'}}$. Accreting neutron stars with Roche-lobe filling companion stars have a high probability of exhibiting eclipses, producing similar time delays but undetectable changes in amplitude and sky location. Even for the most rapidly rotating neutron stars, this time delay only corresponds to a few percent of the phase of the gravitational wave, making it an extremely challenging measurement. However, if sources of continuous gravitational waves exist just below the limit of detection of current observatories, next-generation instruments will be able to observe them with enough precision to measure the signal of an eclipsing star. Detecting this effect would provide a new direct probe to the interior of stars, complementing asteroseismology and the detection of solar neutrinos.