The impact of the crust equation of state on the analysis of GW170817
The impact of the crust equation of state on the analysis of GW170817
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DOI：
10.1088/1361-6382/ab5ba4
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发表时间：
2019-02
影响因子：
3.5
通讯作者：
R. Gamba;J. Read;L. Wade
中科院分区：
文献类型：
--
作者：
R. Gamba;J. Read;L. Wade
GW170817是高级LIGO和处女座观测到的第一颗中子星-中子星合并，它的探测及其后续分析代表了引力波数据对理解致密物质的首次贡献。通过光谱分解参数化两颗中子星状态方程的高密度部分，并对最大质量值施加下限，可以估计出恒星的半径为km和km （Abbott et al . 2018）。Rev. Lett. 121 161101)。然而，这些值没有考虑到由于选择地壳低密度状态方程而产生的任何不确定性，该不确定性被固定以再现SLy状态方程模型（Douchin and Haensel 2001 Astron）。《天文学》380（151）。我们重新分析了GW170817的数据，并确定了不同的地壳模型对中子星的质量和潮汐变形能力没有强烈的影响——用引力波分析无法区分低密度模型。然而，地壳确实对推断出的半径有影响。我们利用中子星结构方程预测了由于这种影响而产生的系统误差，并将预测结果与全参数估计结果进行了比较。对于GW170817，这个系统误差影响了0.3 km的半径估计，大约是中子星的半径。
The detection of GW170817, the first neutron star-neutron star merger observed by Advanced LIGO and Virgo, and its following analyses represent the first contributions of gravitational wave data to understanding dense matter. Parameterizing the high density section of the equation of state of both neutron stars through spectral decomposition, and imposing a lower limit on the maximum mass value, led to an estimate of the stars’ radii of km and km (Abbott et al 2018 Phys. Rev. Lett. 121 161101). These values do not, however, take into account any uncertainty owed to the choice of the crust low-density equation of state, which was fixed to reproduce the SLy equation of state model (Douchin and Haensel 2001 Astron. Astrophys. 380 151). We here re-analyze GW170817 data and establish that different crust models do not strongly impact the mass or tidal deformability of a neutron star—it is impossible to distinguish between low-density models with gravitational wave analysis. However, the crust does have an effect on inferred radius. We predict the systematic error due to this effect using neutron star structure equations, and compare the prediction to results from full parameter estimation runs. For GW170817, this systematic error affects the radius estimate by 0.3 km, approximately of the neutron stars’ radii.