论文标题
柔软X射线瞬变中的中子星的结实结构和热演化
Crust structure and thermal evolution of neutron stars in soft X-ray transients
论文作者
论文摘要
我们研究了物理学对软X射线瞬变（SXTS）中中子恒星热演化的影响。特别是，我们考虑了吸积发作过程中深层加热来源的不同现代模型，以及在地壳形成过程中嵌入的杂质带来的影响。我们在不同的假设和热源和杂质的分布下模拟了中子星的热结构和演变。对于非晶状的外壳，我们考虑地壳形成时会产生的核电荷波动。对于积聚的地壳，我们比较了组成和内部加热的不同理论模型。我们还将数值模拟的结果与SXT MXB 1659-29中的地壳冷却的观察结果进行了比较。我们发现，中子恒星的内壳的非胶合部分可以具有分层结构，几乎纯净的晶体层与由不同核的混合物组成的层互换。后一层具有相对较低的热导率，这会影响瞬变的热演化。地壳中的杂质分布在很大程度上取决于密集物质的模型和地壳形成方案。达成理论和观测之间达成共识所需的浅加热取决于地壳和包膜的特征。
We study the effect of physics input on thermal evolution of neutron stars in soft X-ray transients (SXTs). In particular, we consider different modern models of the sources of deep crustal heating during accretion episodes and the effects brought about by impurities embedded in the crust during its formation. We simulate thermal structure and evolution of episodically accreting neutron stars under different assumptions on the crust composition and on the distribution of heat sources and impurities. For the nonaccreted crust, we consider the nuclear charge fluctuations that arise at crust formation. For the accreted crust, we compare different theoretical models of composition and internal heating. We also compare results of numerical simulations with observations of the crust cooling in SXT MXB 1659-29. We found that the nonaccreted part of the inner crust of a neutron star can have a layered structure, with almost pure crystalline layers interchanging with layers composed of mixtures of different nuclei. The latter layers have relatively low thermal conductivities, which affects thermal evolution of the transients. The impurity distribution in the crust strongly depends on the models of the dense matter and the crust formation scenario. The shallow heating that is needed to reach agreement between the theory and observations depends on characteristics of the crust and envelope.
