Locating the inner edge of the neutron star crust using terrestrial nuclear laboratory data
Locating the inner edge of the neutron star crust using terrestrial nuclear laboratory data
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DOI：
10.1103/physrevc.79.035802
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发表时间：
2008-07
影响因子：
3.1
通讯作者：
Jun Xu;Lie-Wen Chen;Bao-An Li;Hong-ru Ma
中科院分区：
文献类型：
--
作者：
Jun Xu;Lie-Wen Chen;Bao-An Li;Hong-ru Ma
在与中子星外壳相同的亚饱和密度范围内，利用重离子反应的同位旋扩散数据约束的富中子核物质的状态方程，采用动力学和热力学两种方法，确定了中子星液体核与固体壳分离的内缘密度和压力分别为$0.040 {\mathrm{fm}}^{\ensuremath{-}3}\ensuremath{\leqslant}{\ensuremath{\rho}}_{t}\ensuremath{\leqslant}0.065 {\mathrm{fm}}^{\ensuremath{-}3}$和0.01 MeV/ ${\mathrm{fm}}^{3}\ensuremath{\leqslant}{P}_{t}\ensuremath{\leqslant}0.26$ MeV/ ${\mathrm{fm}}^{3}$。这些加上观测到的总转动惯量的最小地壳分数，使我们能够为船帆座脉冲星的半径设定一个新的极限，这与以前的估计有很大的不同。进一步表明，广泛使用的非对称核物质状态方程的抛物近似会系统地导致更高的核壳过渡密度和压力，特别是在更刚性的对称能泛函下。
Within both dynamical and thermodynamical approaches using the equation of state for neutron-rich nuclear matter constrained by the recent isospin diffusion data from heavy-ion reactions in the same subsaturation density range as the neutron star crust, the density and pressure at the inner edge separating the liquid core from the solid crust of neutron stars are determined to be $0.040 {\mathrm{fm}}^{\ensuremath{-}3}\ensuremath{\leqslant}{\ensuremath{\rho}}_{t}\ensuremath{\leqslant}0.065 {\mathrm{fm}}^{\ensuremath{-}3}$ and 0.01 MeV/${\mathrm{fm}}^{3}\ensuremath{\leqslant}{P}_{t}\ensuremath{\leqslant}0.26$ MeV/${\mathrm{fm}}^{3}$, respectively. These together with the observed minimum crustal fraction of the total moment of inertia allow us to set a new limit for the radius of the Vela pulsar significantly different from the previous estimate. It is further shown that the widely used parabolic approximation to the equation of state of asymmetric nuclear matter leads systematically to significantly higher core-crust transition densities and pressures, especially with stiffer symmetry energy functionals.