MRI: Development of Adaptive Optics Upgrade for the CHARA Array - Phase II

在俯瞰洛杉矶的威尔逊山顶上，有六台1米口径的y形望远镜。与其他山顶上的望远镜不同，这六台望远镜不是彼此独立使用的，而是一致使用，有效地形成了一个更大的望远镜，一个干涉阵列，其中每台望远镜的光学和近红外光与相邻望远镜的光结合在一起。6台1米望远镜作为干涉阵列运行，能够探测到天文来源中更精细的细节（空间分辨率），而不是单独使用1米望远镜。6台1米望远镜之间的物理距离从33米到331米不等，空间分辨率优于1毫角秒。这远远超过了最大的地面和轨道望远镜的分辨率，甚至比目前正在开发的超大型望远镜（elt）的分辨率还要高一个数量级。自从乔治亚州立大学高角分辨率天文学中心（CHARA）于2005年完成威尔逊山阵列的建设以来，威尔逊山干涉测量阵列已经产生了第一个直接探测到单个恒星的重力变暗，第一个光晕星的角直径，第一个单一的主序星的图像，第一个相互作用的双星的直接图像。这是发现新星15小时后火球膨胀的第一张照片。这项资助的工作将通过完成6个1米望远镜的自适应光学升级，显著提高干涉测量阵列探测微弱目标的能力（灵敏度）和科学吞吐量。根据观测条件，灵敏度将提高0.5到3个星等，科学吞吐量将提高3-5倍。通过由国家光学天文台（NOAO）管理的开放分配程序，联盟成员和一般天文团体都可以使用威尔逊山干涉仪。通过该阵列，CHARA正在培训干涉测量领域的下一代科学和技术专家，该设施产生的科学成果被纳入本科课程和公共宣传活动。完成威尔森山光学/近红外干涉仪升级的资金是通过NSF的主要研究仪器（MRI）项目提供的。这项资助的工作将完成CHARA阵列自最初建造以来的第一次主要设施升级。乔治亚州立大学的T. ten Brummelaar博士及其合作者仔细考虑了最具成本效益的方法来提高仪器的灵敏度。资助工作的主要目标是在6个1米望远镜中增加可变形镜（DM），完成每个望远镜的全面，快速AO能力的开发和实施。总之，这些改进将使H波段的灵敏度提高0.5到3个星等，并使高质量数据的夜间数量在夏季增加约3倍，在冬季增加5倍，而达到特定信噪比所需的集成时间最多减少3倍。新的重要研究领域包括对高度变红的目标的研究，如年轻恒星周围的碎片盘、金牛座盘和yso上的吸积流。

On the summit of Mt. Wilson overlooking Los Angeles sits a Y-shaped array of six 1-m aperture telescopes. Unlike telescopes located on other mountaintops, these six are not used independently of each other, but are instead used in unison to effectively form a single larger telescope, an interferometric array, in which the optical and near-infrared light from each of the telescopes is combined with the light from its neighbors. Operation of the six 1-m telescopes as an interferometric array results in the ability to detect finer details (spatial resolution) in astronomical sources than would be possible if the 1-m telescopes were utilized individually. With physical separations between the six 1-m telescopes ranging from 33 to 331 meters, spatial resolutions better than 1 milliarcsecond are achieved. This far exceeds the resolution of the largest ground-based and orbiting telescopes, and is even an order of magnitude better than will be possible with the extremely large telescopes (ELTs) currently under development. Since construction of the Mt. Wilson array was completed in 2005 by Georgia State University's Center for High Angular Resolution Astronomy (CHARA), the Mt. Wilson interferometric array has yielded the first direct detection of gravity darkening on a single star, the first angular diameter for a halo population star, the first image of a single, main-sequence star, the first direct image of an interacting binary, and first images of the expanding fireball around a nova just 15 hours after its discovery. The funded work will significantly improve the interferometric array's ability to detect faint targets (sensitivity) and scientific throughput by completing an adaptive optics upgrade for each of the six 1-m telescopes. The sensitivity will be improved by 0.5 to 3 magnitudes, depending on the seeing conditions, and the scientific throughput will be enhanced by a factor of 3-5. Access to the Mt. Wilson interferometer is afforded to consortium members but also to the general astronomical community through an open allocation process managed by the National Optical Astronomy Observatory (NOAO). Through the array, CHARA is training the next generation of scientific and technical experts in the field of interferometry, and scientific results emerging from the facility are incorporated in undergraduate courses as well as public outreach activities. Funding for completing the Mt. Wilson optical/near-IR interferometer upgrade is being provided through the Major Research Instrumentation (MRI) program of the NSF.The funded work will complete the first major facility upgrade of the CHARA array since initial construction. Georgia State's Dr. T. ten Brummelaar and collaborators have carefully considered the most cost-effective approaches to enhance the sensitivity of the instrument. The principal goal of the funded work is to add deformable mirrors (DM) to each of the six 1-m telescopes, completing the development and implementation of full, fast AO capabilities at each telescope. Together, these modifications should yield sensitivity increases 0.5 to 3 magnitudes at H band, and increase the number of nights of high-quality data by about a factor of 3 in the summer and 5 in the winter, with the integration time required to reach a specific SNR reduced by a factor of up to 3. New important areas of study include the study of highly reddened targets such debris disks around young stars, T-Tauri disks, and accretion flows onto YSOs.