发表机构
The Chinese University of Hong Kong; Zentrum für Astronomie der Universität Heidelberg, Astronomisches Rechen-Institut; Heidelberger Institut für Theoretische Studien（香港中文大学; 海德堡大学天文中心计算研究所; 海德堡理论研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过自洽求解两流体方程，发现白矮星中混合少量自湮灭暗物质可解释其质量-半径关系偏差，表明白矮星可作为灵敏暗物质探测器。
AI 中文摘要
白矮星是恒星的致密残骸，由电子简并压力支撑，其结构通常被认为已被充分理解。然而，理论预测与观测到的白矮星质量-半径（MR）关系之间存在显著差异，尤其是对于具有无法解释的热源的热Q分支白矮星。在本研究中，我们通过研究自湮灭暗物质（SADM）混合在白矮星中的效应，探索白矮星作为暗物质（DM）物理探测窗口的可能性，自洽地求解两流体流体静力平衡方程和热扩散方程组。我们获得了白矮星光度$L$和有效温度$T_\text{eff}$作为暗物质质量分数$f_d$、湮灭截面$\langle\sigma v\rangle$、粒子质量$m_\chi$以及白矮星总质量$M_t$函数的经验公式。我们还比较了不同$L$、$f_d$以及费米子和玻色子暗物质粒子统计下白矮星MR关系与观测数据。我们表明，观测到的白矮星MR关系中的大多数偏差可以通过混合有$f_d \le 10^{-5}$和$\langle\sigma v\rangle \ll 3\times10^{-26}$ $\text{cm}^3$ $\text{s}^{-1}$（热遗迹截面）的SADM来解释。因此，我们的结果表明，白矮星可以作为灵敏的暗物质探测器，暗物质自湮灭可以为白矮星提供额外加热，从而解释其观测到的额外光度。
英文摘要
White dwarfs (WDs) are compact remnants of stars, supported by electron degeneracy pressure, and their structures are generally considered to be well understood. Significant discrepancies exist between the theoretical and observed white dwarf mass-radius (MR) relations, especially for hot Q-branch white dwarfs with unexplained heating sources. In this study, we explore the potential of WDs as a portal to dark matter (DM) physics by investigating the effect of self-annihilating DM (SADM) admixed in WDs, solving the set of two-fluid hydrostatic equilibrium and heat diffusion equations self-consistently. We obtain empirical formulae for the WD luminosity $L$ and effective temperature $T_\text{eff}$ as functions of the DM mass fraction $f_d$, annihilation cross section $\langleσv\rangle$, and particle mass $m_χ$, as well as the WD's total mass $M_t$. We also compare the WD MR relations for various $L$, $f_d$, and both Fermionic and Bosonic DM particle statistics, with the observational data. We show that the majority of observed deviations in the WD MR relation can be accounted for by having SADM admixed with $f_d \le 10^{-5}$ and $\langleσv\rangle \ll 3\times10^{-26}$ $\text{cm}^3$ $\text{s}^{-1}$, the thermal relic cross section. Therefore, our results suggest that WDs can be sensitive DM detectors, and DM self-annihilation could provide additional heating in WDs, accounting for their observed extra luminosities.
