Are Active Galactic Nuclei accretion disks too big?

所有主要星系似乎都藏匿着一个超大质量黑洞，质量是太阳的数百万倍，位于它们的中心。这些黑洞对它们所在星系的生长和演化方式有着重要的影响。黑洞生长的一种重要方式是通过一种称为吸积的过程，即热气体通过圆盘螺旋进入黑洞。最近的研究表明，这些吸积盘比理论上预期的要大好几倍。由于这些天体距离如此之远，天文学家无法直接拍摄这些圆盘的照片，因此必须使用间接技术。在这个项目中，PI将使用一种称为混响映射的技术。它使用光的回声来确定吸积盘的大小，就像声纳使用声音的回声来绘制海底地图一样。利用专用的机器人望远镜，PI每年将监测大约10个超大质量黑洞吸积盘，以测试为什么吸积盘看起来太大，并更好地了解黑洞是如何增长的。在更广泛的影响领域，PI将把这个项目的科学整合到底特律当地的学校。2超大质量黑洞在它们所在的星系的生长和演化中扮演着重要的角色。它们的主要生长方式是通过圆盘吸积气体。然而，对这些吸积盘结构的观测探测很少，特别是因为它们太小、太远，不能直接在空间上分辨。在这个项目中，PI将使用一种被称为混响映射的技术，该技术测量光的回声来确定吸积盘的大小。最近几项使用这种技术的研究表明，这些磁盘比预期的要大2-3倍。为了更好地理解这一点，我们将使用一台专用的机器人望远镜，每年监测大约10个超大质量黑洞吸积盘，建立一个大量的样本。此外，PI将应用新的分析技术进一步测试回声的来源，并测试为什么这些吸积盘看起来太大。在更广泛的影响领域，PI将把这个项目的科学融入底特律当地的学校。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Part 1All major galaxies appear to harbor a supermassive black hole, millions of times the mass of our Sun, residing at their center. These black holes have an important influence over the way their host galaxies grow and evolve. An important way in which the black hole grows is through a process called accretion, where hot gas spirals into the black hole via a disk. Recent studies suggest that these accretion disks are several times larger than expected by theory. As these objects are so distant astronomers cannot take direct pictures of the disks themselves and so must use indirect techniques. In this project, the PI will use a technique called reverberation mapping. This uses echoes of light to determine the size of the accretion disks, much like sonar uses echoes of sound to map the ocean floor. Using a dedicated robotic telescope the PI will monitor approximately 10 supermassive black hole accretion disks per year to test why accretion disks appear too big, and better understand how black holes grow. In the area of Broader Impacts, the PI will integrate the science of this project into local Detroit schools.Part 2Supermassive black holes play an important role in the growth and evolution of the galaxies in which they reside. A principal way in which they grow is via the accretion of gas via a disk. However, observational probes of the structure of these accretion disks are rare, especially since they are too small and distant to spatially resolve directly. In this project, the PI will use a technique known as reverberation mapping which measures echoes of light to determine the size scale of the accretion disks. Several recent studies using this technique suggest that these disks are a factor of 2 - 3 larger than expected. To better understand this we will use a dedicated robotic telescope to monitor approximately 10 supermassive black hole accretion disks per year building a substantial sample. Furthermore, the PI will apply novel analysis techniques to further test of origin of the echoes, and test why these accretion disks appear too big. In the area of Broader Impacts, the PI will integrate the science of this project into local Detroit schools.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.