European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching-bei-München, Germany.
Nature. 2013 Feb 21;494(7437):328-30. doi: 10.1038/nature11819. Epub 2013 Jan 30.
The masses of the supermassive black holes found in galaxy bulges are correlated with a multitude of galaxy properties, leading to suggestions that galaxies and black holes may evolve together. The number of reliably measured black-hole masses is small, and the number of methods for measuring them is limited, holding back attempts to understand this co-evolution. Directly measuring black-hole masses is currently possible with stellar kinematics (in early-type galaxies), ionized-gas kinematics (in some spiral and early-type galaxies) and in rare objects that have central maser emission. Here we report that by modelling the effect of a black hole on the kinematics of molecular gas it is possible to fit interferometric observations of CO emission and thereby accurately estimate black-hole masses. We study the dynamics of the gas in the early-type galaxy NGC 4526, and obtain a best fit that requires the presence of a central dark object of 4.5(+4.2)(-3.1) × 10(8) solar masses (3σ confidence limit). With the next-generation millimetre-wavelength interferometers these observations could be reproduced in galaxies out to 75 megaparsecs in less than 5 hours of observing time. The use of molecular gas as a kinematic tracer should thus allow one to estimate black-hole masses in hundreds of galaxies in the local Universe, many more than are accessible with current techniques.
在星系隆起中发现的超大质量黑洞的质量与多种星系性质相关联，这表明星系和黑洞可能是共同演化的。可靠测量的黑洞质量数量较少，并且测量它们的方法数量有限，这阻碍了对这种共同演化的理解。目前，通过恒星运动学（在早型星系中）、离子化气体运动学（在一些旋涡和早型星系中）以及具有中心脉泽发射的稀有物体，可以直接测量黑洞质量。在这里，我们报告说，通过模拟黑洞对分子气体动力学的影响，可以拟合 CO 发射的干涉观测，从而准确估计黑洞质量。我们研究了早型星系 NGC 4526 中气体的动力学，并获得了一个最佳拟合，要求存在一个中心暗物体，质量为 4.5(+4.2)(-3.1)×10(8)太阳质量（3σ置信限）。在下一代毫米波干涉仪中，这些观测结果可以在不到 5 小时的观测时间内在 75 兆秒差距外的星系中重现。因此，使用分子气体作为运动学示踪剂应该可以在本地宇宙中估计数百个星系的黑洞质量，这比当前技术所能达到的星系数量要多得多。
