Science Commissioning of the MMT's Ground-Layer Adaptive Optics System

自适应光学(AO)是一种技术，它允许天文学家校正望远镜接收到的图像，以消除光线穿过地球大气层时产生的扭曲。近年来，这项技术取得了重大进展，它的使用正在增加，并成为世界上大多数最大望远镜的常规使用。既然自动对焦技术既强大又可靠，科学家和工程师们正在寻求将其应用到更广泛的视野中，以便能够以相同的高分辨率一次看到更大的物体或星团。亚利桑那大学的迈克尔·哈特博士一直在为位于亚利桑那州南部霍普金斯山上的MMT天文台探索这条道路。这一宽广的视场将通过使用五颗地面激光导航星来实现，这些激光导航星分布在6.5米望远镜的两角分钟视场内。通过快速测量这些导航星在视场中的变形，并用MMT的自适应次镜进行校正，整个视场的高空间分辨率正在实现。随着研发工作接近完成，哈特博士现在将开始该项目的最后阶段，以使AO系统完全强大，并与能够使用6.5米望远镜的科学家使用的仪器相结合。新的能力将使天文台更有效率(对给定亮度的物体需要更少的望远镜时间)，并允许对结构细节进行更详细的研究。这项工作得到了美国国家科学基金会天文科学部先进技术和仪器计划的支持。

Adaptive Optics (AO) is a technique that allows astronomers to correct images received by a telescope for the distortions introduced as the light passes through the earth's atmosphere. The technique has made significant advances in recent years and its use is increasing and becoming routine at most of the world's largest telescopes. Now that AO is robust and reliable, scientists and engineers are seeking to apply it to a wider field of view so that larger objects or clusters of objects can all be viewed with the same high resolution at once. Dr. Michael Hart, of the University of Arizona, has been pursuing such a path for the MMT Observatory on Mount Hopkins in southern Arizona. This wide field will be realized by employing five ground-layer laser guide stars spread over a two arcminute field of view of the 6.5-meter telescope. By rapidly measuring the distortions of these guide stars over the field of view and correcting them with the MMT's adaptive secondary mirror, high spatial resolution over the entire field is being achieved. With the development effort nearly completed, Dr. Hart will now begin the last stage of the project to make the AO system fully robust and integrated with the instruments used by the scientists who have access to the 6.5-meter telescope. The new capability will make the observatory more efficient (less telescope time will be needed for objects of a given brightness) and allow for more detailed studies of structural details. This work is supported by NSF's Division of Astronomical Sciences program for Advanced Technologies and Instrumentation.