厚盘，薄希望：AGN中被抑制的捕获和并合率
Thick Disks, Thin Hopes: Suppressed Capture and Merger Rates in AGN
AI总结：
研究指出，AGN盘的厚度对引力交叉截面介导的过程速率有强烈反比影响，强调需考虑盘参数如 aspect ratio 和压力源以准确预测这些速率。
摘要：
多年来，多个模型被提出以解释围绕超大质量黑洞的吸积盘结构和支撑，从标准的薄热压主导α盘模型到更近期描述几何更厚辐射或磁或湍流主导盘的模型。无论如何，嵌入盘中的物体（如致密物体、恒星、气体、尘埃）可以经历引力和水动力相互作用，导致如双星相互作用/捕获、引力波并合事件、动态摩擦、吸积、间隙打开等有趣过程。长期以来，认为AGN盘可以增强这些事件的速率；然而，几乎所有分析都假设了特定的薄盘模型（aspect ratios H/R ≲ 0.01）。本文显示，由引力交叉截面介导的过程的速率与厚度H/R有非常强的反比关系（按(H/R)^{-8}陡峭地变化），且H/R在盘外（这些过程常被引用的地方）可因假设的压力支撑来源而变化达>1000倍。这预测某些模型中速率可降低十万个数量级，表明在计算这些速率的有意义预测时，必须考虑盘参数如aspect ratio和不同的盘压力源。例如，如果磁压在盘外重要，如最近的工作所建议，捕获速率将比之前忽略磁压的研究降低10^{10}-10^{20}倍。
英文摘要：
Multiple models have been suggested over the years to explain the structure and support of accretion disks around supermassive black holes, from the standard thin thermal-pressure-dominated $α$-disk model to more recent models that describe geometrically thicker radiation or magnetic or turbulence-dominated disks. In any case, objects embedded in the disk (e.g. compact objects, stars, gas, dust) can undergo gravitational and hydrodynamic interactions with each other leading to interesting processes such as binary interaction/capture, gravitational wave merger events, dynamical friction, accretion, gap opening, etc. It has long been argued that disks of active galactic nuclei (AGN) can enhance the rates for many of these events; however, almost all of that analysis has assumed specific thin-disk models (with aspect ratios $H/R \lesssim 0.01$). We show here that the rates for processes such as these that are mediated by gravitational cross-sections has a very strong inverse dependence on the thickness $H/R$ (scaling as steeply as $(H/R)^{-8}$), and $H/R$ can vary in the outer disk (where these processes are often invoked) by factors $\gtrsim 1000$ depending on the assumed source of pressure support in the disk. This predicts rates that can be lower by tens of orders-of-magnitude in some models, demonstrating that it is critical to account for disk parameters such as aspect ratio and different sources of disk pressure when computing any meaningful predictions for these rates. For instance, if magnetic pressure is important in the outer disk, as suggested in recent work, capture rates would be suppressed by factors $\sim 10^{10}-10^{20}$ compared to previous studies where magnetic pressure was ignored.
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。
