HJST Coudé光谱仪大气色散校正器与图像旋转器的光机设计（麦克唐纳天文台）
Optomechanical design of an ADC and image rotator for the HJST Coudé Spectrograph at McDonald Observatory
- McDonald Observatory, The University of Texas at Austin（麦克唐纳天文台，德克萨斯大学奥斯汀分校）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文介绍了麦克唐纳天文台 HJST Coudé 光谱仪旋转式大气色散校正器的光机设计，采用反向旋转 Amici 棱镜校正色散，并探讨了 K 镜图像旋转器作为未来升级，以提升高分辨率光谱观测性能。
AI中文摘要：
高分辨率光谱观测要求稳定的狭缝照明，并需减轻大气折射效应对吞吐量和光谱保真度的不利影响。我们介绍了 Harlan J. Smith 2.7 米望远镜上 Coudé Tull 光谱仪旋转式大气色散校正器（RADC）的光学与机械设计。大气色散引起随波长变化的图像位移，该位移随天顶距增大而增加，在天顶角 65° 时，在 350-1000 nm 波长范围内可达约 4 角秒，导致与波长相关的狭缝损失和非均匀狭缝照明。RADC 采用一对反向旋转的 Amici 棱镜，在可操作的天顶角范围内提供连续校正，同时保持图像质量并与现有 coudé 预狭缝光学元件兼容。我们介绍了可部署 ADC 子系统的光学与机械设计、其在有限中继包络内的集成，以及其对吞吐量和狭缝照明稳定性的预期影响。此外，我们讨论了一种 K 镜图像旋转器，作为未来升级的潜在方案，用于观测扩展和非点状目标，在长时间积分期间可能希望保持天空上的固定狭缝位置角。我们简要总结了图像旋转概念及其在 HJST coudé 中继内集成考虑的初步光学研究。总之，这些发展支持增强 HJST 上高分辨率光谱学的观测能力。
英文摘要：
High-resolution spectroscopic observations require stable slit illumination and mitigation of atmospheric refraction effects that degrade throughput and spectral fidelity. We present the optical and mechanical design of a Rotational Atmospheric Dispersion Corrector (RADC) for the coudé Tull Spectrograph on the Harlan J. Smith 2.7 m Telescope. Atmospheric dispersion introduces wavelength-dependent image displacement that increases with zenith distance and reaches approximately 4 arcsec across the 350 - 1000 nm wavelength range at a zenith angle of 65°, leading to wavelength-dependent slit losses and non-uniform slit illumination. The RADC employs a pair of counter-rotating Amici prisms to provide continuous correction over the operational zenith-angle range while maintaining image quality and compatibility with the existing coudé pre-slit optics. The optical and mechanical design of the deployable ADC subsystem, its integration within the limited relay envelope, and its expected impact on throughput and slit illumination stability are presented. In addition, we discuss a K-mirror image rotator as a potential future upgrade for observations of extended and non-point-like targets, where maintaining a fixed slit position angle on the sky may be desirable during long integrations. Preliminary optical studies of the image-rotation concept and its integration considerations within the HJST coudé relay are briefly summarized. Together, these developments support enhanced observing capabilities for high-resolution spectroscopy on the HJST.
