The gravitational-wave signal GW190814 involves a compact object with mass ( 2.50 − 2.67 ) M ⊙ $(2.50-2.67)~{\mathrm{M}}_{\odot }$ within the so-called low mass gap. As yet, a general consensus on its nature, being a black hole, a neutron star or an exotic star, has not been achieved. We investigate the possibility this compact object to be an anisotropic neutron star. Anisotropies in a neutron star core arise naturally by effects such as superfluidity, hyperons, strong magnetic fields and allow the maximum mass to exceed that of the ideally isotropic stars. We consider the Krori-Barua ansatz to model an anisotropic core and constrain the equation of state with LIGO/Virgo observations GW170817 and GW190814. We find that the GW190814 secondary component can be an anisotropic neutron star compatible with LIGO/Virgo constraints if the radius attains a value in the range ( 13.2 − 14.0 ) km $(13.2-14.0)~{\mbox{km}}$ with the anisotropic core’s boundary density in the range ( 3.5 − 4.0 ) ⋅ 10 14 g / cm 3 $(3.5-4.0)\cdot 10^{14}~{\mbox{g}}/{\mbox{cm}}^{3}$ .

中文翻译：

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作为各向异性中子星的引力波信号 GW190814 的次级分量

引力波信号 GW190814 涉及一个质量为 ( 2.50 − 2.67 ) M ⊙ $(2.50-2.67)~{\mathrm{M}}_{\odot }$ 的致密物体，位于所谓的低质量间隙内。迄今为止，尚未就其本质是黑洞、中子星还是奇异星达成普遍共识。我们研究了这个致密天体是各向异性中子星的可能性。中子星核心的各向异性是由超流、超子、强磁场等效应自然产生的，并且允许最大质量超过理想各向同性恒星的质量。我们考虑 Krori-Barua ansatz 来模拟各向异性核心并用 LIGO/Virgo 观测 GW170817 和 GW190814 约束状态方程。