发表机构
University of Michigan; Brigham Young University; University of Science, VNU-HCM; Viet Nam National University Ho Chi Minh City; University of Vienna（密歇根大学; 杨百翰大学; 越南国立大学胡志明市分校科学大学; 越南国立大学胡志明市; 维也纳大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究以ALMA观测NGC 315的CO(2-1)气体数据，用多种动力学建模方法测其超大质量黑洞质量，发现气体与恒星动力学测量存在32%偏差，该星系可作为黑洞质量测量方法的基准。
AI 中文摘要
我们呈现ALMA第7周期对NGC 315核周盘的CO(2-1)观测，角分辨率为0.230角秒×0.175角秒，较以往测量有所提升，且分辨率足以分辨超大质量黑洞（SMBH）的影响球（SOI），该黑洞质量此前估算为M_BH=(2.08^{+0.33}_{-0.15})×10^9 M☉。高空间分辨率与灵敏度实现了对分子气体运动学的可靠全立方体正向建模，可直接对比多种独立的基于气体的动力学建模技术。我们将采用马尔可夫链蒙特卡洛（MCMC）与嵌套采样方法的标准贝叶斯代码，以及一种频率论代码应用于同一数据集，探究恒星质量分布、气体面亮度参数化与盘几何带来的系统不确定性。所有方法得出的黑洞质量一致，表明推导的M_BH对方法的依赖性不强。结合所有独立的基于分子气体的模型，我们得出集成中位数黑洞质量为M_BH/10^9 M☉=2.02^{+0.04}_{-0.05}(统计)^{+0.05}_{-0.04}(系统)，其中总误差预算中，建模系统误差与形式拟合不确定性的贡献相当。我们的M_BH与经验性的M_BH-σ_★和M_BH-核球光度（L_bulge）标度关系一致，且比独立的恒星动力学测量值低32%，我们在气体与恒星方法的系统差异背景下讨论这一偏差。NGC 315可作为量化分子气体动力学M_BH系统不确定性，以及未来气体与恒星动力学方法交叉对比的基准。
英文摘要
We present ALMA Cycle~7 \cotwo\ observations of the circumnuclear disk in NGC~315 at an angular resolution of $0\farcs230\times0\farcs175$, improving on past measurements and resolving the sphere of influence (SOI) of the supermassive black hole (SMBH), whose mass has previously been estimated of $M_{\rm BH}= \left(2.08^{+0.33}_{-0.15}\right) \times 10^9$~M$_\odot$ The high spatial resolution and sensitivity enable robust full-cube forward modeling of the molecular gas kinematics and a direct comparison of multiple independent gas-based dynamical modeling techniques. We apply standard Bayesian codes using both MCMC and nested sampling approaches, as well as a frequentist code to the same dataset, exploring systematic uncertainties associated with the stellar mass distribution, gas surface-brightness parameterization, and disk geometry. All methods yield consistent black hole masses, indicating that the inferred $M_{\rm BH}$ is not strongly method-dependent. Combining the ensemble of independent molecular-gas-based models, we derive an ensemble median black hole mass of $M_{\rm BH}/10^9\,\mathrm{M_\odot} = 2.02^{+0.04}_{-0.05}$(stat)$^{+0.05}_{-0.04}$(sys), where the comparable contributions to the full error budget arise from modeling systematics rather than formal fitting uncertainties. Our $M_{\rm BH}$ is consistent with the empirical $M_{\rm BH}$--$σ_\star$ and $M_{\rm BH}$--$L_{\rm bulge}$ scaling relations, and lies 32\% below an independent stellar-dynamical measurement, a discrepancy we discuss in the context of systematic differences between gas- and stellar-based methods. NGC~315 serves as a benchmark for quantifying molecular gas-dynamical $M_{\rm BH}$ systematic uncertainties and for future cross-comparisons of gaseous and stellar dynamical approaches.
Comments26 pages, 12 Figures, 3 Tables. Accepted to ApJ
