Implications of supermassive neutron stars for the form of the equation of state of hybrid stars
Implications of supermassive neutron stars for the form of the equation of state of hybrid stars
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DOI：
10.1103/physrevc.108.025801
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发表时间：
2023-08
影响因子：
3.1
通讯作者：
Hongyi Sun;Dehua Wen
中科院分区：
文献类型：
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作者：
Hongyi Sun;Dehua Wen
PSRJ0952-0607和GW190814事件中的第二个天体的观测表明，可能存在超大质量中子星。本文采用等声速参数描述夸克物质的物态方程，通过Maxwell和Gibbs结构研究了超大质量混合星物态方程参数的约束。结果表明，要支持超大质量混合星，较低的跃迁能量密度、较小的能量密度间断和较高的夸克物质声速是有利的。对于所建立的混合星EOS模型，如果能量密度不连续的值大于$180，则相应混合星的最大质量将不满足GW190814中第二天体的质量下限。此外，还证实了超大质量中子星观测也可以排除双子星的存在，因为超大质量混合星需要相对较小的能量密度不连续。最后，我们给出了中子星无因次潮汐变形性下限的粗略估计，范围为2到3。
The observations of PSR J0952-0607 and the second object in GW190814 event indicate the possible existence of supermassive neutron stars. In this work, by using the Constant-Sound-Speed (CSS) parametrization to describe the equation of state (EOS) of quark matter, the constraints on the EOS parameters from supermassive hybrid stars are investigated through the Maxwell and Gibbs constructions. It is shown that to support a supermassive hybrid star, a lower transition energy density, a smaller energy density discontinuity and a higher sound speed of quark matter are favored. For the constructed hybrid star EOS model, the maximum mass of the corresponding hybrid stars will not meet the lower mass limit of the second object in GW190814 if the energy density discontinuity takes a value higher than $180~{\rm MeV~fm^{-3}}$. Moreover, it is confirmed that the supermassive neutron star observation can also rule out the existence of twin stars as a supermassive hybrid star requires a relatively small energy density discontinuity. Finally, we give a rough estimate of the lower limit of the dimensionless tidal deformability of neutron stars which ranges from 2 to 3.