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arXiv 2406.14906astro-ph.HEnucl-th
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用于参数估计的统一壳核状态方程的中子星性质推断

Inference of neutron-star properties with unified crust-core equations of state for parameter estimation

P. J. Davis, H. Dinh Thi, A. F. Fantina, F. Gulminelli, M. Oertel, L. Suleiman

AI总结:

提出数值工具CUTER,通过一致匹配核物理壳层与高密度核心状态方程,减少中子星性质推断中因壳层处理不一致导致的误差和不确定性低估。

摘要:

关联不同的全局中子星(NS)性质,例如潮汐形变与半径,或者质量与半径,需要状态方程(EoS)。因此,确定 NS EoS 不仅是各种观测项目的科学目标,也进入了分析过程;例如,在双中子星合并的旋近阶段,通过引力波(GW)从测得的潮汐形变预测 NS 半径。为此,估计 EoS 的理论不确定性非常重要,其中之一是来自低密度区域处理不一致可能带来的偏差;即使用所谓的非统一 NS 壳层。我们提出一种数值工具,允许用户将核物理信息壳层一致地匹配到描述恒星核心的任意高密度 EoS。我们引入了饱和密度附近 EoS 的反演程序,允许用户提取核物质参数,并以一致方式将 EoS 扩展到更低密度。对于壳层中非均匀物质的处理,我们的工作采用了基于可压缩液滴(CLD)模型的标准方法。我们还展示了在高密度区域使用参数化不可知 EoS 表示的贝叶斯分析,以量化壳层处理不一致引起的不确定性。我们表明,使用固定、现实但不一致的壳层模型会在全局 NS 性质估计中导致小但可避免的误差,并导致 NS 性质推断中不确定性的低估。我们的结果强调了在推断方案中使用一致 EoS 的重要性。我们为重建这种热力学一致 EoS 而开发的数值工具 CUTER,已经过测试和验证,可供天体物理界使用。

英文摘要:

Relating different global neutron-star (NS) properties, such as tidal deformability and radius, or mass and radius, requires an equation of state (EoS). Determining the NS EoS is therefore not only the science goal of a variety of observational projects, but it also enters in the analysis process; for example, to predict a NS radius from a measured tidal deformability via gravitational waves (GW) during the inspiral of a binary NS merger. To this aim, it is important to estimate the theoretical uncertainties on the EoS, one of which is the possible bias coming from an inconsistent treatment of the low-density region; that is, the use of a so called non-unified NS crust. We propose a numerical tool allowing the user to consistently match a nuclear-physics informed crust to an arbitrary high-density EoS describing the core of the star. We introduce an inversion procedure of the EoS close to saturation density that allows users to extract nuclear-matter parameters and extend the EoS to lower densities in a consistent way. For the treatment of inhomogeneous matter in the crust, a standard approach based on the compressible liquid-drop (CLD) model approach was used in our work. A Bayesian analysis using a parametric agnostic EoS representation in the high-density region is also presented in order to quantify the uncertainties induced by an inconsistent treatment of the crust. We show that the use of a fixed, realistic-but-inconsistent model for the crust causes small but avoidable errors in the estimation of global NS properties and leads to an underestimation of the uncertainties in the inference of NS properties. Our results highlight the importance of employing a consistent EoS in inference schemes. The numerical tool that we developed to reconstruct such a thermodynamically consistent EoS, CUTER, has been tested and validated for use by the astrophysical community.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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