A Leap in Sensitivity for CHARA/CLASSIC Optical Interferometry for Astronomy

光学干涉测量使用一组较小的望远镜连接在一起，以达到数百米望远镜的角度分辨率。这种干涉仪具有超大望远镜的分辨率，但具有小型望远镜的灵敏度。他们可以看到恒星的细节，但迄今为止只能看到相对明亮的恒星。该项目的主要目标是提高其中一个干涉仪的灵敏度，该干涉仪被称为高角分辨率天文学中心（CHARA）阵列，位于威尔逊山天文台。对照相机、光学玻璃和数据记录的翻新将使研究比目前可能的暗淡10倍的恒星成为可能。这种灵敏度的提高将使研究能够了解宇宙中是否存在生命，并开辟新的研究领域。该项目还将包括在CHARA游客中心增设新设施，每年接待15,000名游客，并与美国自然历史博物馆合作，在CHARA游客中心展示最新的科学简报。CHARA阵列最长基线的角直径测量值在K波段小至0.7 mas，在r波段提高到0.2 mas。CHARA可以分辨从O型到m型的所有主序星盘，而下一代单口径望远镜将无法分辨主序星。地基干涉测量中最重要的问题是灵敏度。该项目将使CLASSIC/CLIMB光束合并器在近红外波段的极限提高2个星等。这将通过用现代的基于SELEX MOVPE sapira的检测系统取代20年的PICNIC探测器来实现。这次升级还将包括H和K波段的光谱分辨率，两个波段的同时观测，以及偏振分裂。随着灵敏度的提高，它将有可能调查更大范围的恒星直径和温度，年轻恒星周围的圆盘，大质量恒星的风，相互作用和分离的双星，瞬态事件，以及通过由NSF/MSIP资助的社区访问计划为客座观测者开辟新的机会。更高的灵敏度也将极大地扩大观测活动星系核（AGN）核心的能力。CHARA首次可以直接确认或否定AGN核中的二元结构。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Optical interferometry uses an array of smaller telescopes connected together to achieve the angular resolution of telescopes many hundreds of meters across. Such interferometers have the resolution of extremely large telescopes but have the sensitivity of small telescopes. They can see stars in exquisite detail but can so far only see relatively bright stars. The main goal of this project is to improve the sensitivity of one of these interferometers called the Center for High Angular Resolution Astronomy (CHARA) Array, which is located at Mount Wilson Observatory. Renovations to the camera, optical glass, and data recording will enable studying stars 10 times fainter than currently possible. Such improved sensitivity will enable investigations that may inform whether life may exist elsewhere in the universe, and open up new areas of research. This program will also include new facilities in the CHARA visitor center, which hosts 15,000 visitors each year, and a collaboration with the American Museum of Natural History to display current science bulletins at the CHARA visitor center.The CHARA Array longest baseline yields angular diameter measurements as small as 0.7 mas in K band improving to 0.2 mas at R. CHARA can resolve stellar disks all along the main sequence from O- to M-types, whereas there will be no main sequence stars resolvable by the next generation of single aperture telescopes. The most significant problem in ground based interferometry is sensitivity. This program will increase the limit of the CLASSIC/CLIMB beam combiner by 2 magnitudes in the near infrared. This will be achieved by replacing the 20-year-old PICNIC detector with a modern SELEX MOVPE SAPHIRA based detection system. This upgrade will also include spectral resolution in both H and K bands, simultaneous observation in both bands, and a polarization split. With enhanced sensitivity it will be possible to survey a much broader range of stellar diameters and temperatures, the disks around young stars, winds from massive stars, interacting and detached binary stars, transient events, as well as open up new opportunities for guest observers through the community access program funded by NSF/MSIP. More sensitivity will also vastly expand the ability to observe the cores of Active Galactic Nuclei (AGN). The CHARA could directly confirm or deny a binary structure in an AGN core for the first time.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.