GW170817: Measurements of Neutron Star Radii and Equation of State
GW170817: Measurements of Neutron Star Radii and Equation of State
复制标题
DOI：
10.1103/physrevlett.121.161101
复制
发表时间：
2018-10-15
影响因子：
8.6
通讯作者：
Zweizig, J.
中科院分区：
文献类型：
--
作者：
Abbott, B. P.;Abbott, R.;Zweizig, J.
2017年8月17日，LIGO和处女座天文台首次直接探测到中子星双星系统合并产生的引力波。GW170817引力波信号的探测为在这些恒星内部发现的极端条件下直接探测物质的性质提供了一个新的机会。最初对LIGO和Virgo数据的最小假设分析限制了汇聚体的潮汐效应，然后将其转化为对中子星半径的限制。在这里，我们通过假设两个天体都是由相同的状态方程描述的中子星，并在银河系双星中子星中观察到的范围内自转，来扩展以前的分析。我们的分析使用了两种方法：使用中子星各种宏观性质之间的状态方程不敏感关系和使用状态方程本身的定义函数p(Rho)的有效参数化。仅根据LIGO和Virgo数据和第一种方法，我们在90%的可信度水平上测量了两颗中子星的半径，对于较重的恒星，R-1=10.8(-1.7)(+2.0)公里，对于较轻的恒星，R-2=10.7(-1.5)(+2.1)公里。如果再按电磁观测的要求要求状态方程支持质量大于1.97M圆点的中子星，并采用状态方程参数化，则在90%的可信水平上进一步约束R-1=11.9(-1.4)(+1.4)Km和R2=11.9(-1.4)(+1.4)Km。最后，我们得到了在核以上密度下对p(Rho)的限制，在两倍核饱和密度下测得的压力为3.5(-1.7)(+2.7)×10(34)dyn cm(-2)，在90%水平上。
On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(rho) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R-1 = 10.8(-1.7)(+2.0) km for the heavier star and R-2 = 10.7(-1.5)(+2.1) km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97 M-circle dot as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R-1 = 11.9(-1.4)(+1.4) km and R-2 = 11.9(-1.4)(+1.4) km at the 90% credible level. Finally, we obtain constraints on p(rho) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5(-1.7)(+2.7) x 10(34) dyn cm(-2) at the 90% level.