Updated universal relations for tidal deformabilities of neutron stars from phenomenological equations of state
Updated universal relations for tidal deformabilities of neutron stars from phenomenological equations of state
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DOI：
10.1103/physrevd.103.063036
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发表时间：
2020-12
影响因子：
5
通讯作者：
D. Godzieba;R. Gamba;D. Radice;S. Bernuzzi
中科院分区：
文献类型：
--
作者：
D. Godzieba;R. Gamba;D. Radice;S. Bernuzzi
中子星（NS）致密性、其多极潮汐变形系数之间以及双星系统潮汐参数之间的状态方程（EOS）不敏感关系，即所谓的普遍关系，对于打破引力波数据分析中的简并性至关重要。在这里，我们使用大量近 200 万个与当前观察结果一致的现象学 EOS 来验证和重新校准这些普遍关系。在此过程中，我们将通用关系扩展到 EOS 参数空间的更大区域，尤其是更软的 EOS 和更大的紧致性。我们表明，忽略 NS 的高阶潮汐变形的波形模型从 $20\,{\rm Hz}$ 到合并累积了高达 $3.5$ 的相移弧度。我们还对 GW170817 数据执行完整的贝叶斯参数估计，并比较使用文献中的通用关系生成的 NS 半径约束和我们在此提出的更新拟合。我们发现新拟合产生的 NS 半径小了约 500 米。这种差异小于 GW170817 信噪比半径的统计不确定性，但明显大于下一代探测器的预期精度。
Equation of state (EOS) insensitive relations, so-called universal relations, between the neutron star (NS) compactness, its multipolar tidal deformability coefficients, and between the tidal parameters for binary systems are essential to break degeneracies in gravitational wave data analysis. Here, we validate and recalibrate these universal relations using a large set of almost 2 million phenomenological EOSs that are consistent with current observations. In doing so, we extend universal relations to a larger region of the EOS parameter space, most notably to softer EOSs and larger compactnesses. We show that waveform models that neglect higher-than-leading-order tidal deformations of the NSs accumulate as much as $3.5$ radians of dephasing from $20\,{\rm Hz}$ to merger. We also perform a full Bayesian parameter estimation of the GW170817 data, and we compare the NS radius constraints produced using universal relations from the literature and the updated fits we propose here. We find that the new fits yield a NS radius that is smaller by about 500 meters. This difference is less than the statistical uncertainty on the radius at the signal-to-noise-ratio of GW170817, but it is significantly larger than the precision anticipated for next-generation detectors.