发表机构
Institute of Science and Technology Austria (ISTA); Niels Bohr International Academy, Niels Bohr Institute; Space Telescope Science Institute; Johns Hopkins University; Columbia University; New York University（奥地利科学技术研究院; 尼尔斯·玻尔国际学院，尼尔斯·玻尔研究所; 太空望远镜科学研究所; 约翰斯·霍普金斯大学; 哥伦比亚大学; 纽约大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过流体动力学模拟研究逆行共转盘中的偏心超大质量双黑洞，发现不同小盘旋转方向导致圆形或偏心内旋，并预测了可探测的电磁辐射。
AI 中文摘要
环绕超大质量双黑洞（SMBHBs）的共转盘预计会在广泛的倾角范围内形成，其中逆行构型可能是一种常见现象。本文首次对偏心超大质量双黑洞周围的逆行共转盘进行了基于网格的流体动力学模拟，求解了平衡粘性加热和激波加热与黑体辐射冷却的能量方程。我们研究了不同的初始盘马赫数 $\mathcal{M}_a \in \{10, 20, 40\}$，并考虑了双星偏心率 $e_\mathrm{b}\in[0.0,\\,0.8]$，发现对于相同的双星偏心率和马赫数，存在多个稳定态。这些态的区别在于其小盘（minidisks）的旋转方向：两者均为逆行（$\downarrow\downarrow$）、两者均为顺行（$\uparrow\uparrow$），或一顺一逆（$\uparrow\downarrow$），该性质由初始条件决定。我们的研究结果表明，每种态都会产生性质上不同的轨道演化：$\downarrow\downarrow$ 和 $\uparrow\downarrow$ 小盘驱动圆形内旋，而 $\uparrow\uparrow$ 小盘驱动偏心内旋，并可能在LISA频带内产生可观测的偏心率。我们测量了盘产生的电磁辐射，发现质量为 $M_\mathrm{b}=8\times10^6\mathrm{M}_\odot$、红移 $z=1$ 的双星可被当前和未来的光学及紫外仪器探测到。我们证明了时间和方位角平均的盘轮廓可以很好地用一维模型描述，该模型自然地设定了一个腔半径，在此半径内角动量输运由雷诺应力而非粘性主导。
英文摘要
Circumbinary disks around supermassive black hole binaries (SMBHBs) are expected to form across a broad range of inclinations, with retrograde configurations potentially a common occurrence. Here we present the first grid-based hydrodynamical simulations of retrograde circumbinary disks around eccentric SMBHBs, solving an energy equation that balances viscous and shock heating against blackbody radiative cooling. We investigate different initial disk Mach numbers $\mathcal{M}_a \in \{10, 20, 40\}$ and consider binary eccentricities $e_\mathrm{b}\in[0.0,\,0.8]$, finding that multiple stable states exist for the same binary eccentricity and Mach number. These states differ by the sense of rotation of their minidisks; both retrograde ($\downarrow\downarrow$), both prograde ($\uparrow\uparrow$), or one of each ($\uparrow\downarrow$), a property set by the initial conditions. Our findings indicate that each state produces qualitatively distinct orbital evolution: $\downarrow\downarrow$ and $\uparrow\downarrow$ minidisks drive circular inspirals whereas $\uparrow\uparrow$ minidisks drive eccentric inspirals with potentially observable eccentricity in the LISA band. We measure the electromagnetic emission produced by the disk, finding that a binary of mass $M_\mathrm{b}=8\times10^6\mathrm{M}_\odot$ at redshift $z=1$ would be detectable by both current and upcoming optical and UV instruments. We demonstrate that the time- and azimuthally-averaged disk profiles are well described by 1D models, which naturally set a cavity radius within which angular momentum transport is dominated by Reynolds stresses rather than viscosity.
CommentsSubmitted to MNRAS, comments are welcome
