Development of Technologies to Enable High Contrast, High Resolution, Low Emissivity Imaging at Visible and Thermal Wavelengths with the Magellan Adaptive Secondary AO System

天文自适应光学系统可以分为两种基本类型：1)配备自适应光学平台的标准望远镜，该平台包括传输光学、波前传感器、滤光片和一个或多个可变形镜；2)将自适应二次镜（ASM）直接集成到望远镜本身，减少反射次数，并在仪器聚焦的整个过程中保持光学系统的清洁。后一种方案在某些方面更加困难和昂贵，但已经证明了最高的望远镜图像质量，以及在红外方面提供更好的性能。在南半球安装ASM技术的唯一例子是由Laird Close博士及其来自亚利桑那大学和阿塞特里天文台（意大利）的合作者在智利拉斯坎帕纳斯的6.5米克莱麦哲伦望远镜上安装的585执行器二级。镜子就位后，克洛斯博士正计划对仪器进行升级，以充分利用大幅锐化的图像。提出了两项改进：1)增强电子器件和智能？2)精确的日冕掩膜和振动控制，允许在1-5微米范围内成像和光谱学，在ao锐化场中，明亮的中心物体被遮挡。用这些系统进行的初步科学研究包括：对来自成熟巨型系外行星的反射可见光进行高对比度成像（这是发现真正地球的关键一步），对演化恒星的质量损失、热恒星周围电离气体区域的结构、太阳系小行星和卫星的表面，以及对新发现的年轻多尘系外行星进行高对比度的L和M波段（3.5和5微米）成像/光谱分析。克洛斯在指导和合作学生和年轻教师方面表现出色，他目前的活动也不例外。新的自适应光学探测器系统也将提供给其他可以使用麦哲伦望远镜的人，并希望在重新协商公共访问私人资助的设施时提供给一般天文社区。美国国家科学基金会天文科学部通过其先进技术和仪器项目，为麦哲伦望远镜自适应光学系统开发新的成像和光谱能力提供资金。

Astronomical adaptive optics systems can be classified into two basic types: 1) a standard telescope equipped with an adaptive optics bench that includes transfer optics, wavefront sensors, filters, and one or more deformable mirrors, and 2) a system that incorporates an adaptive secondary mirror (ASM) directly into the telescope itself, reducing the number of reflections and preserving a clean optical system all the way to the instrument focus. The latter scheme is in some ways more difficult and expensive to achieve, but has demonstrated the highest on-telescope image quality, as well as providing far better performance in the infrared.The sole example of installed ASM technology in the southern hemisphere is the 585 actuator secondary installed by Dr. Laird Close and collaborators from The University of Arizona and Arcetri Observatory (Italy) on the 6.5m Clay Magellan telescope at Las Campanas, Chile. With the mirror now in place, Dr. Close is planning instrumental upgrades to make use of the greatly sharpened images. Two improvements are proposed: 1) enhanced electronics and a ?smart?, high-speed shutter that will limit exposure only to intervals of excellent correction and thereby enable high-resolution imaging in the optical (wavelengths of ~0.6 nm), and 2) precise coronagraphic masks and vibration control to allow 1-5 micron imaging and spectroscopy of sources in the AO-sharpened field with a bright central object obscured. Initial science to be performed with these systems includes high-contrast imaging of reflected visible light from mature giant exoplanets (a key step towards discovering true Earths), the mass-loss from evolved stars, structures of ionized gas regions around hot stars, surfaces of solar-system asteroids and moons, and high-contrast L and M band (3.5 and 5 microns) imaging/spectroscopy of newly-discovered young dusty exoplanets.Dr. Close has demonstrated an excellent history of mentoring and collaborating with students and young faculty, and his current activities are no exceptions. The new adaptive optics detector systems will also be made available to others with access to the Magellan telescopes, and hopefully to the general astronomical community when public access to privately-funded facilities is renegotiated.Funding for the development of new imaging and spectroscopic capabilities for the Magellan telescope adaptive optics systems is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.