小红点的暗物质起源：早期播种与超邦迪吸积
A Dark-matter Origin of Little Red Dots: Early Seeding and Super-Bondi Accretion
- Peking University（北京大学）
- Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）
- Beijing Normal University（北京师范大学）
- School of Physics and Astronomy, Beijing Normal University（北京师范大学物理学院）
- University of Chinese Academy of Sciences（中国科学院大学）
- School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究提出自相互作用暗物质的引力热坍缩可早期产生黑洞种子，并通过超邦迪吸积驱动其成长为超大质量黑洞，从而解释小红点的异常性质，为暗物质微观物理提供新探针。
AI中文摘要：
"小红点"（LRDs）是早期宇宙中一类正在吸积的超大质量黑洞（SMBHs），它们通常表现出质量不足甚至无法探测到的恒星宿主。它们的早期出现、高空间密度以及极大的黑洞-恒星质量比，对依赖重子物质形成和增长黑洞的传统播种方案构成了严峻挑战。在此，我们证明如果暗物质具有自相互作用，上述异常现象可以自然得到解决。我们应用了一个完全相对论性的、非平衡的暗物质晕演化模型（该模型最初在我们早期的工作中开发），来追踪自相互作用暗物质（SIDM）晕从初始坍缩形成黑洞种子到随后暗物质吸积的完整引力热演化过程。我们发现，在再电离之前形成的、高度集中的暗物质晕中，引力热坍缩能在几亿年内有效地产生恒星质量的黑洞种子。值得注意的是，与暗物质吸积的标准预期相反，SIDM中的热传导随后维持了长时间的超级邦迪内流，在没有任何重子辅助的情况下，将这些种子驱动到超大质量尺度，直至LRD时代。完成这些过程所需的暗物质晕条件，以及避免破坏引力热演化的重大并合的概率，共同产生了一个与观测到的LRD丰度和红移分布相一致的SMBH种群。我们的发现建立了一条路径，即超大质量黑洞主要在暗物质中播种和组装，远在大量星系围绕它们形成之前，从而为LRDs提供了令人信服的物理解释，并为暗物质微观物理学提供了新的观测探针。
英文摘要：
The "Little red dots" (LRDs) are a population of accreting supermassive black holes (SMBHs) in the early Universe which often exhibit undermassive or even undetectable stellar hosts. Their early emergence, high space density, and extremely large black-hole-to-stellar mass ratios pose a serious challenge to conventional seeding scenarios that rely on baryon for both the formation and growth of black holes. Here we demonstrate that the above anomalies can be naturally resolved if dark matter is self-interacting. We apply a fully relativistic, non-equilibrium halo-evolution model, first developed in our earlier work, to trace the complete gravothermal evolution of self-interacting dark matter (SIDM) halos, from the initial collapse into BH seeds to the subsequent accretion of dark matter. We find that in highly concentrated halos assembled before reionization, gravothermal collapse efficiently produces stellar-mass black-hole seeds within a few hundred million years. Remarkably, and contrary to standard expectations for dark-matter accretion, heat conduction in SIDM then sustains a prolonged super-Bondi inflow that drives these seeds to supermassive scale by the LRD epoch, without baryonic assistance. The halo conditions required for completing these processes, together with the probability of avoiding major mergers that disrupt gravothermal evolution, result in an SMBH population consistent with the observed abundance and redshift distribution of LRDs. Our findings establish a pathway in which SMBHs are seeded and assembled primarily from dark matter, well before substantial galaxies form around them, thereby offering both a compelling physical explanation for LRDs and a new observational probe of dark-matter microphysics.
