Hyperon Effects on the Spin Parameter of Rotating Neutron Stars
Hyperon Effects on the Spin Parameter of Rotating Neutron Stars
复制标题
DOI：
10.1088/0256-307x/32/11/112101
复制
发表时间：
2015-12
影响因子：
3.5
通讯作者：
B. Qi;Naibo Zhang;S. Y. Wang;B. Sun
中科院分区：
文献类型：
--
作者：
B. Qi;Naibo Zhang;S. Y. Wang;B. Sun
基于相对论平均场理论中的物态方程，研究了均匀自转中子星的无量纲自旋参数j=Cj/(Gm(2))。结果表明，以开普勒星频率f(K)自转的中子星的自旋参数j(Max)的最大值与恒星质量M>；0.5M(圆点)时的0.7值相近，这一点适用于不同版本的无超子和有超子状态方程。在没有超子的模型中，j与标度自转频率f/f(K)之间的关系对恒星质量或所采用的状态方程不敏感。然而，中子星中超子的出现将导致自旋参数j的不确定性，这反过来又可能导致在吸盘致密恒星系统中观察到的准周期振荡的理论研究的复杂性。
Based on the equations of state from the relativistic mean field theory without and with the inclusion of strangeness-bearing hyperons, we study the dimensionless spin parameter j = cJ/(GM(2)) of uniformly rotating neutron stars. It is shown that the maximum value of the spin parameter j(max) of a neutron star rotating at the Keplerian frequency f(K) is j(max) similar to 0.7 when the star mass M > 0.5M(circle dot), which is sustained for various versions of equations of state without and with hyperons. The relationship between j and the scaled rotation frequency f/f(K) is found to be insensitive to the star mass or the adopted equation of state in the models without hyperons. However, the emergence of hyperons in neutron stars will lead to an uncertainty of the spin parameter j, which in turn could generate a complexity in the theoretical study of the quasi-periodic oscillations observed in disk-accreting compact-star systems.