源PSR J0740+6620的半径观测在约束核物质对称能上的应用

Application of the Radius Observation of Source PSR J0740+6620 on the Constraints of the Nuclear Matter Symmetry Energy

在本研究中,采用中子星模型与贝叶斯方法相结合的理论框架,研究了NICER合作组发布的质量相关的半径数据和源PSR J0740+6620的最大质量数据对致密丰中子核物质状态方程的约束情况。研究了当分别关闭对称能的高阶项、保持饱和密度处核物质状态方程参数的恒定以及保持对称核物质状态方程参数恒定时对核物质状态方程的约束情况。计算结果显示:在高密度区域,对称能的值有所不同,但在两倍饱和密度以下的密度范围内,它们大致相同,表明在两倍饱和密度以下的密度范围内,本研究的结果不依赖于所使用的参数化的核物质状态方程。

In this study,a theoretical framework combining the neutron star model and the Bayesian inference method is used to investigate the constraints on the equation of state of dense neutron-rich nuclear matter based on the mass radius data released by the NICER collaboration and the maximum mass data of the source PSR J0740+6620.The constraints on the equation of state are separately examined when the high-order terms of the symmetry energy are turned off,the saturation density parameters of the equation of state are fixed,and the parameters describing the symmetric nuclear matter are fixed.The calculated results indicate a difference in the symmetry energy values in the high density region,but they are roughly the same within the density range below twice the saturation density,indicating that the results of this study are independent of the parameterized equation of state used within that density range.