论文标题
带有低$λ/d $ iwa和中等光谱带宽的带冠
A Coronagraph with a Sub-$λ/D$ IWA and a Moderate Spectral Bandwidth
论文作者
论文摘要
未来的高对比度成像光谱和大型分段望远镜将能够检测G型或K型主序列恒星周围的地球样行星的大气分子。增加目标行星的数量将需要具有较小的内部工作角度（IWA）的冠状动脉，如果我们增强各种可检测到的大气分子，则需要宽光谱带宽。为了满足这些要求，在本文中，我们提出了一个冠状系统，该系统在中等波长的频段上提供的IWA小于1 $λ_0 / d $，其中$λ_0$是设计中心波长，$ d $表示望远镜的矩形光圈的完整宽度。性能模拟表明，所提出的系统大约在650--750nm的波长上以1 $λ_0 / d $在1 $λ_0 / d $下的对比度达到$ 10^{-10} $。此外，该系统在输入分离角$ \ sim $ 0.7--1.4 $λ_0 / d $;在输入分离角处具有核心吞吐量$ \ geq $ 10 \％;为了减少望远镜时间，我们需要其他观察方法的事先信息，以高于视野宽度的精度。对于某些类型的畸变，包括倾斜异差，该拟议的系统的灵敏度比以往任何时候的coronagraph都具有约1λ_0/d $的iWAS。在未来对类似地球行星的观察中，拟议的冠状动脉系统可能是一种辅助性冠状动脉系统，致力于实现极小的IWA。
Future high-contrast imaging spectroscopy with a large segmented telescope will be able to detect atmospheric molecules of Earth-like planets around G- or K-type main-sequence stars. Increasing the number of target planets will require a coronagraph with a small inner working angle (IWA), and wide spectral bandwidth is required if we enhance a variety of detectable atmospheric molecules. To satisfy these requirements, in this paper, we present a coronagraphic system that provides an IWA less than 1$λ_0 / D$ over a moderate wavelength band, where $λ_0$ is the design-center wavelength and $D$ denotes the full width of the rectangular aperture included in the telescope aperture. A performance simulation shows that the proposed system approximately achieves a contrast below $10^{-10}$ at 1$λ_0 / D$ over the wavelengths of 650--750nm. In addition, this system has a core throughput $\geq$ 10\% at input separation angles of $\sim$ 0.7--1.4$λ_0 / D$; to reduce telescope time, we need prior information on the target's orbit by other observational methods to a precision higher than the width of the field of view. For some types of aberration including tilt aberration, the proposed system has a sensitivity less than ever-proposed coronagraphs that have IWAs of approximately $1λ_0/D$. In future observations of Earth-like planets, the proposed coronagraphic system may serve as a supplementary coronagraphic system dedicated to achieving an extremely small IWA.
