Rapidly rotating Δ-resonance-admixed hypernuclear compact stars
Rapidly rotating Δ-resonance-admixed hypernuclear compact stars
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DOI：
10.1016/j.physletb.2020.135812
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发表时间：
2020-09
影响因子：
4.4
通讯作者：
J. Li;A. Sedrakian;F. Weber
中科院分区：
文献类型：
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作者：
J. Li;A. Sedrakian;F. Weber
我们使用一组从协变密度泛函理论导出的强子状态方程来研究它们的高密度行为对快速旋转的Δ共振混合高超子致密星的特性的影响。特别是，我们系统地探索了体积能量等标偏度 Q sat 和对称能量斜率 L sym 的变化对快速旋转致密星质量的影响。由于状态方程模型满足所有现代天体物理约束，只有在以下三种条件下才能获得约 2.5 M⊙ 的过大引力质量：(a) 核物质中具有强吸引力的 Δ 共振势，(b) 最大快速（开普勒）旋转，以及 (c) 参数范围 Q sat≳ 500 MeV 和 L sym≲ 50 MeV。 Q sat 和 L sym 的这些值与协变核子密度泛函的大样本（总共约 260 个）参数化有相当小的重叠。要求(a)-(c)的极端性质强化了这样的理论预期：GW190814事件涉及的次要天体很可能是低质量黑洞而不是超大质量中子星。
We use a set of hadronic equations of state derived from covariant density functional theory to study the impact of their high-density behavior on the properties of rapidly rotating Δ-resonance-admixed hyperonic compact stars. In particular, we explore systematically the effects of variations of the bulk energy isoscalar skewness, Q sat, and the symmetry energy slope, L sym, on the masses of rapidly rotating compact stars. With models for equation of state satisfying all the modern astrophysical constraints, excessively large gravitational masses of around 2.5 M⊙ are only obtained under three conditions:(a) strongly attractive Δ-resonance potential in nuclear matter,(b) maximally fast (Keplerian) rotation, and (c) parameter ranges Q sat≳ 500 MeV and L sym≲ 50 MeV. These values of Q sat and L sym have a rather small overlap with a large sample (total of about 260) parametrizations of covariant nucleonic density functionals. The extreme nature of requirements (a)-(c) reinforces the theoretical expectation that the secondary object involved in the GW190814 event is likely to be a low-mass black hole rather than a supramassive neutron star.