Cooling of hypernuclear compact stars: Hartree–Fock models and high-density pairing
Cooling of hypernuclear compact stars: Hartree–Fock models and high-density pairing
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DOI：
10.1093/mnras/stz1459
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发表时间：
2019-03
影响因子：
4.8
通讯作者：
A. Raduta;J. Li;A. Sedrakian;F. Weber
中科院分区：
文献类型：
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作者：
A. Raduta;J. Li;A. Sedrakian;F. Weber
在Hartree和Hartree-Fock近似下，用协变密度泛函理论建立恒星模型，研究了超核致密恒星的热演化。这两种类型的参数化都符合致密恒星的天体物理质量限制和现有的超核数据。我们讨论了这些密度泛函的不同，并强调了它们对超核星的组成和冷却的影响。结果表明，用具有低对称能量斜率的密度泛函模型计算的超核星，L，与观测到的致密星的冷却数据相当一致。这类基于较大L值的恒星模型在低密度下产生了直接的URCA过程，从而导致明显更快的冷却。我们推测了P波通道中质子和Λ的S的高密度配对，并提供了简单的标度论据来获得这些能隙。因此，质量为1.8≤M/M的最大质量恒星模型⊙≤2经历了涉及Λ、S和质子的超音速DUrca过程的较慢冷却。
The thermal evolution of hypernuclear compact stars is studied for stellar models constructed on the basis of covariant density functional theory in Hartree and Hartree–Fock approximation. Parametrizations of both types are consistent with the astrophysical mass constraints on compact stars and available hypernuclear data. We discuss the differences of these density functionals and highlight the effects they have on the composition and on the cooling of hypernuclear stars. It is shown that hypernuclear stars computed with density functional models that have a low symmetry energy slope, L, are fairly consistent with the cooling data of observed compact stars. The class of stellar models based on larger L values gives rise to the direct Urca process at low densities, which leads to significantly faster cooling. We conjecture high-density pairing for protons and Λ’s in the P-wave channel and provide simple scaling arguments to obtain these gaps. As a consequence the most massive stellar models with masses 1.8 ≤ M/M⊙ ≤ 2 experience slower cooling by hyperonic dUrca processes which involve Λ’s and protons.