中子星可观测量与不同密度段核物质状态方程的关联

中子星物质主要是由高密度非对称核物质组成。目前通过地面重离子碰撞等实验来认识高密度非对称核物质的物态还存在很大的不确定性。随着对中子星天文观测精度的提高以及可观测量的增多，基于对中子星的天文观测来反向约束高密度非对称核物质物态成为了可能。从理论上去探讨中子星的可观测量与不同密度段物态方程的关联程度，将有助于上述反向对中子星物质物态的研究。本文利用分段式多方物态方程，通过对中子星的半径(R)、潮汐形变参数($\varLambda$)、转动惯量(I)等可观测量的计算分析，给出了这些观测量与物态方程各密度段的关联度。结果表明，质量为1.4$ M_{\odot}$的典型中子星潮汐形变参数($\varLambda$)和f-模频率($\nu$)主要与$ 0.5\rho_{\rm{sat}} \sim 1.5\rho_{\rm{sat}}$、$ 2.5\rho_{\rm{sat}} \sim 3.5\rho_{\rm{sat}}$和$3.5\rho_{\rm{sat}} \sim $$ 4.5\rho_{\rm{sat}}$ 三个密度段物态方程有较强关联；中子星半径(R)主要与$ 1.5\rho_{\rm{sat}} \sim 3.5\rho_{\rm{sat}}$及壳层物态有较强关联；转动惯量(I)与$ 4.5\rho_{\rm{sat}}$以下各密度段均有一定关联。

Correlation Between Neutron Star Observation and Equation of State of Nuclear Matter at Different Densities

Neutron star matter is mainly composed of asymmetric dense nuclear matter. At present, there is still great uncertainty in the understanding of the high-density asymmetric nuclear matter through the terrestrial experiments, such as the heavy ion collisions. With the improvement of astronomical observation accuracy and the increase of observable measurements of neutron stars, it is possible to reverse constraint the state of high-density nuclear matter based on astronomical observation of neutron stars. Theoretically investigating the correlation between the observable measurements of neutron stars and the equation of states (EOSs) at different density sections will be helpful to the research of the reverse constraints. In this work, by employing the piecewise polytrope EOSs, the observable measurements of the radius(R), tidal deformability($\varLambda$), moment of inertia(I) of the neutron star $etc$. are calculated and analyzed, and the correlations between these observations and each density segment of the EOSs are given. The results show that tidal deformability ($\varLambda$) and f-mode frequency ($\nu$) of a canonical neutron star ($M \!=\! 1.4\, M_{\odot}$) are mainly correlated with $0.5\rho_{\rm{sat}} \!\sim\! 1.5\rho_{ sat}$, $2.5\rho_{\rm{sat}} \!\sim\! 3.5\rho_{\rm{sat}}$ and $3.5\rho_{\rm{sat}} \!\sim\! 4.5\rho_{\rm{sat}}$ segments of EOSs; the neutron star radius (R) are mainly correlated with $1.5\rho_{\rm{sat}} \!\sim\! 3.5\rho_{\rm{sat}}$ and the crust segments of EOSs; the moment of inertia (I) are mainly correlated with the density below $ 4.5\rho_{\rm{sat}}$ segments of EOSs.