AI 中文总结
研究双超大质量黑洞吸积，考虑吸积理论等进展，聚焦特定系统和质量比范围，构建含三个盘的双星系统模型，自洽计算辐射贡献，分析光谱能量分布及双星演化，为宽带观测测试提供依据。
AI 中文摘要
双（超）大质量黑洞预计存在于某些星系中心。本文重新审视双超大质量黑洞的吸积，纳入吸积理论和两黑洞间质量传输率的最新进展。聚焦总黑洞质量为\(10^8\,M_\odot\)、爱丁顿比为\(0.1\)的相对明亮系统，考虑\(10^{-4} \le q \le 0.5\)的广泛质量比范围。该双星系统由围绕两个黑洞的两个迷你盘和围绕双星质量中心的一个环双星盘组成。根据质量比，两个迷你盘可为热吸积流、标准薄（冷）盘或苗条盘。自洽考虑所有三个盘（可能处于不同吸积模式）的辐射贡献。双黑洞系统的光谱能量分布在近红外到紫外波段呈现普遍的“缺口”特征，不同质量比的双星具有不同的光谱能量分布特性，为未来宽带观测提供测试机会。还研究了这些双星系统的演化，发现初始质量比\(q \lesssim \text{a few} \times 10^{-3}\)的系统，质量比向平衡值\(q \sim 10^{-3}\)演化；初始质量比更大的系统，质量比则向统一值演化。
英文摘要
Binary (super-)massive black holes (BHs) are expected to reside in the center of some galaxies. In this work, we re-visit accretion onto binary massive BHs, incorporating recent advances in both accretion theory and the mass transfer rate between the two massive BHs. We focus on relatively bright systems with an Eddington ratio of 0.1 for a binary with total BH mass $10^8\,M_\odot$, but consider a wide range of mass ratios $10^{-4} \le q \le 0.5$. The binary system consists of two mini-disks surrounding two individual BHs and a circumbinary disk surrounding the mass center of binary BHs. Depending on the mass ratio, the two mini-disks can be hot accretion flows, standard thin (cold) disks, or Slim disks. The radiative contributions from all three disks, each potentially in different accretion modes, are taken into account self-consistently. The spectral energy distributions of the binary BH system show universal ``notch'' features from the near-infrared to ultraviolet bands, caused by the gap or cavity in the accretion disk, consistent with previous studies. Binary with different mass ratios exhibit distinct spectral energy distribution properties, offering opportunities for testing (identifying candidates) with future broad band (infrared up to X-rays) observations. We also investigate the evolution of these binary systems, and find that, for systems with initial mass ratios $q \lesssim \text{a few} \times 10^{-3}$, the mass ratio evolves toward an equilibrium value $q \sim 10^{-3}$. For binary BH systems with a larger initial mass ratio, their mass ratio instead evolves toward unity.
Comments21 pages, 10 figures, 2 tables, to appear in ApJ
