A Laser Guide Star Adaptive Optics Study of Stellar Dynamics at the Galactic Center: A Laboratory for Understanding Interactions with a Central Supermassive Black Holes

近年来，利用世界上最大的红外望远镜进行衍射限制红外观测，在研究银河系中心方面取得了许多最令人兴奋和最重要的突破。Drs。安德里亚·盖兹和马克·莫里斯（加州大学洛杉矶分校）将进行一项为期五年的银河系中心研究计划，该计划有三个主要目标：1)通过恒星轨道获得银河系中心引力势的精确测量。这将提供一个到银河系中心的距离值，精确度超过百分之一，并给出银河系中心超大质量黑洞（SMBH）的黑洞伴星的质量限制或值。这些决定是初步的，也是必不可少的，对于这个项目在强引力制度下的广义相对论效应的长期研究，以及已经提出存在于那里的暗物质的扩展分布，2)使用恒星动力学来区分试图解释SMBH附近令人费解的年轻恒星存在的理论。这将包括首次测量被认为位于最近在中央秒差距发现的恒星盘中的恒星的偏心率，而不需要先验地假设圆盘成员。类似的测量也将提供强大的约束或测量，任何在大质量年轻星团拱门中心的中等质量黑洞。3)测量在以SMBH为中心的动态放松的恒星尖端的老恒星分布，以测试恒星动力学模型和核SMBH生长。在大多数情况下，从该提案中描述的研究得出的结论也可以应用于其他螺旋星系，从而阐明其中心SMBHs的演化，以及这些SMBHs与周围恒星的形成、动力学和命运的相互作用。这个项目的一个重要方面是展示激光引导星自适应光学（LGSAO）的力量，它最近才在8到10米级望远镜上实施。虽然这项技术是未来大型地面望远镜的关键组成部分，但它尚未被天文学界完全接受。此外，拟议工作的各个方面将为未来LGSAO系统的设计和操作提供参考。在教育方面，该团队将广泛传播他们对银河系SMBH及其周围环境的研究结果，这些结果对公众具有巨大的吸引力，通过制作公开可用的本科教科书和课程材料，纪录片，博物馆展览和公开演讲。他们还将继续培训和指导大量未被充分代表的少数民族，特别是女性，她们被这个项目的成功和盖兹博士鼓励年轻女性进入科学领域的承诺所吸引。

In recent years, diffraction-limited infrared observations with the world's largest infrared telescopes have yielded many of the most exciting and important breakthroughs in the study of the center of our Galaxy. Drs. Andrea Ghez and Mark Morris (University of California - Los Angeles) will conduct a five-year program of Galactic center research which has three primary objectives: 1) Obtain a precision measurement of the Galaxy's central gravitational potential with stellar orbits. This will provide a value of the distance to the Galactic Center to better than one percent accuracy and give a limit or a value for the mass of a black hole companion to the super-massive black hole (SMBH) at the Galactic Center. These determinations are preliminary to, and essential for, this program's long-term investigation of general relativistic effects in the strong gravity regime and of the extended dark matter distribution that has been proposed to exist there, 2) Use stellar dynamics to discriminate between theories attempting to account for the puzzling presence of young stars near the SMBH. This will include the first measurements of eccentricities for stars thought to reside in the stellar disk recently discovered in the central parsec, without the a priori assumption of disk membership. Similar measurements will also provide strong constraints, or measurement, of any intermediate-mass black holes at the center of the massive young star cluster, the Arches, and 3) Measure the distribution of old stars in the dynamically relaxed stellar cusp centered on the SMBH in order to test models of stellar dynamics and of nuclear SMBH growth. The conclusions drawn from the research described in this proposal can, in most cases, be applied to other spiral galaxies as well, thereby elucidating the evolution of their central SMBHs, and the interplay of those SMBHs with the formation, dynamics and fate of their surrounding stars.One important aspect of this project is in demonstrating the power of laser guide star adaptive optics (LGSAO), which has only recently been implemented on 8 to 10 meter-class telescopes. While this technology is a key component of future large ground-based telescopes, it has yet to be fully accepted by the astronomical community. Furthermore, aspects of the proposed work will inform the design and operation of future LGSAO systems. In terms of education, the team will widely disseminate their results on our Galaxy's SMBH and its surroundings, which have tremendous appeal to the general public, by creating publically-available material for undergraduate textbooks and course material, documentaries, and museum exhibits and giving public talks. They will also continue to train and mentor a large number of underrepresented minorities, particularly women, who are attracted to working on this program by its success and the commitment of Dr. Ghez to encouraging young women into science.