论文标题
光谱四阶冠状动脉表征陆地行星在宿主星的小角度分离处的表征
Spectroscopic fourth-order coronagraph for the characterization of terrestrial planets at small angular separations from host stars
论文作者
论文摘要
我们提出了一种在适度观察带宽中分割的望远镜在衍射极限处进行高对比度成像的新方法。这个概念称为“光谱四阶Coronagraphy”，是基于四阶冠状动物，并带有焦平面膜，可调节沿一个方向的空气磁盘的复杂振幅。虽然使用复杂振幅掩码的冠状动脉可以实现任何任意学生的理论极限性能，但焦平面掩膜严重限制了带宽。在这里，重点介绍了焦平面掩模沿一个方向调节复合幅度的事实，我们注意到可以针对光谱仪生成的每个光谱元件进行优化掩模。我们将四阶冠冕与两个光谱仪相结合，以在焦平面上产生出色的光谱，并在Lyot停止上重建白人学生。基于对使用Offner型成像光谱仪的光学设计的波前分析，我们发现该概念的可实现对比度为10^{ - 10}，在1.2-1.5倍的衍射极限范围内的衍射范围为650-750 nm的波长范围内，对于Luvoir望远镜的入口处。因此，这种冠状动脉概念不仅可以使新的可居住星球候选者不仅在20-30 pc以上，而且还可以使附近的M型恒星周围的恒星带来。这种方法有可能促进附近陆地行星的大气的表征，并以未来的上和离轴分割大型望远镜。
We propose a new approach for high-contrast imaging at the diffraction limit using segmented telescopes in a modest observation bandwidth. This concept, named "spectroscopic fourth-order coronagraphy", is based on a fourth-order coronagraph with a focal-plane mask that modulates the complex amplitude of the Airy disk along one direction. While coronagraphs applying the complex amplitude mask can achieve the theoretical limit performance for any arbitrary pupils, the focal plane mask severely limits the bandwidth. Here, focusing on the fact that the focal-plane mask modulates the complex amplitude along one direction, we noticed that the mask can be optimized for each spectral element generated by a spectrograph. We combine the fourth-order coronagraph with two spectrographs to produce a stellar spectrum on the focal plane and reconstruct a white pupil on the Lyot stop. Based on the wavefront analysis of an optical design applying an Offner-type imaging spectrograph, we found that the achievable contrast of this concept is 10^{-10} at 1.2 - 1.5 times the diffraction limit over the wavelength range of 650 - 750 nm for the entrance pupil of the LUVOIR telescope. Thus, this coronagraph concept could bring new habitable planet candidates not only around G- and K-type stars beyond 20 - 30 pc but also around very nearby M-type stars. This approach potentially promotes the characterization of the atmospheres of nearby terrestrial planets with future on- and off-axis segmented large telescopes.
