论文标题
低质量中子星星的引力波动术
Gravitational wave asteroseismology for low-mass neutron stars
论文作者
论文摘要
从冷低质量中子星体中的基本模式引力波系统地研究了以核饱和参数为特征的各种状态方程（EOSS），尤其是以第一压力（$ p_1 $ - ）模式的避免交叉的现象。我们发现，可以避免过境的$ f $ mmode频率和中子星的平均密度可以表示为参数的函数$η$，即核饱和参数的特定组合。由于这些关系，我们可以得出低质量中子星的经验公式，该公式表示$ f $ mmode频率，其中央密度大于避免交叉处的中子恒星的中心密度，这是$η$的函数，其函数是$η$的，而恒星平均密度的平方根是$ x $。另一方面，我们还得出了表达中子星的$ f $ mode频率的经验公式，中子恒星的中心密度小于避免过境的中子恒星的中心密度，这是$ x $的函数，该函数与采用的EOS独立于$ x $。此外，采用$ x $的经验公式作为$η$和$ u_c $的函数，这是恒星中央密度与饱和密度的比例，我们还可以将我们的经验公式重写用于$ f $ mmode频率的经验公式与$η$和$最u_c $的函数。因此，通过观察低质量中子恒星的$ f $ mmode重力波，其质量或重力红移是已知的，人们可以评估$η$和$ u_c $的值，这使我们能够严重限制EOS的中性恒星物质。
The fundamental ($f$-) mode gravitational waves from cold low-mass neutron stars are systematically studied with various equations of state (EOSs) characterized by the nuclear saturation parameters, especially focusing on the phenomena of the avoided crossing with the first pressure ($p_1$-) mode. We find that the $f$-mode frequency and the average density for the neutron star at the avoided crossing can be expressed as a function of the parameter, $η$, which is the specific combination of the nuclear saturation parameters. Owing to these relations, we can derive the empirical formula expressing the $f$-mode frequency for a low-mass neutron star, whose central density is larger than that for the neutron star at the avoided crossing, as a function of $η$ and the square root of the stellar average density, $x$. On the other hand, we also derive the empirical formula expressing the $f$-mode frequency for a neutron star, whose central density is less than that for the neutron star at the avoided crossing, as a function of $x$ independently of the adopted EOS. Furthermore, adopting the empirical formula of $x$ as a function of $η$ and $u_c$, which is the ratio of the stellar central density to the saturation density, we can also rewrite our empirical formula for the $f$-mode frequency to a function of $η$ and $u_c$. So, by observing the $f$-mode gravitational wave from a low-mass neutron star, whose mass or gravitational redshift is known, one could evaluate the values of $η$ and $u_c$, which enables us to severely constrain the EOS for neutron star matter.
