Collaborative Research: High Contrast Imaging at the Photon Noise Limit: On-Sky Validation of Speckle Reconstruction from WFS Telemetry

合作研究：光子噪声极限下的高对比度成像：WFS 遥测斑点重建的空中验证

• 批准号: 2308352
• 负责人: Richard Frazin
• 金额: $ 23.84万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2308352&HistoricalAwards=false
• 关键词: Collaborative; Research; Contrast; Imaging; Photon

Imaging extrasolar planets is challenging. Planets are typically one hundred thousand to ten billion times fainter than their host stars. Taking pictures of such planets requires nearly perfect control of light. Starlight is blocked using optical devices called "coronagraphs". Ground-based telescopes must deal with the additional problem of turbulence in the Earth's atmosphere. Turbulence causes the stars to twinkle, and telescopes remove this twinkle using a technique called "Adaptive Optics". Finally, image processing is performed to find the exoplanet signal in the noise. Current instruments do not image the faintest possible planets because they are limited by “speckles”, which are created by imperfections in all of the above steps. However not all the available information is currently used when analyzing such images. Nearly all image processing methods use only the science images themselves. This creates many biases and artifacts. This is especially true close to the star, where most planets can be found. The goal of this project is to find more planets by using all the combined information. Software will be written for two existing instruments, which will be used by astronomers to analyze their images. This software will be written to be easy to use and made freely available to astronomers. Students will be involved at both participating institutions.Direct imaging characterization of exoplanets has so far been limited to young, hot, and massive planets orbiting relatively far from their stars. Such planets are observable due to their intrinsic self-luminosity generated as they continue to cool after formation. Many more planets are observable if the inner working angle can be improved. Moreover, improving the sensitivity limit of high-contrast imaging will enable the characterization of fainter, lower-mass planets. The key to enabling more sensitive post-processing is to use the data simultaneously recorded by the suite of wavefront sensors (WFSs) in a modern high-contrast imaging system. These include the main high-order WFS as well as coronagraph low-order and focal plane WFS. The investigators, with the assistance of a post-doctoral researcher, will implement algorithms based on existing proofs of concept, test and validate these algorithms with lab and on-sky data, and deploy the software systems on the MagAO-X and SCExAO instruments. These two extreme-AO coronagraphic instruments share a common software framework and there is collaboration between the instrument teams. This system will be deployed so that users can use it to reduce their data to achieve the highest possible sensitivity at small separations. Making a telemetry-based post-processing system available on current generation instruments will dramatically improve their sensitivity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

为太阳系外行星成像是一项具有挑战性的工作。行星通常比它们的主恒星暗十几万到一百亿倍。拍摄这样的行星需要近乎完美的光线控制。星光被称为“日冕图”的光学设备阻挡。地面望远镜必须处理地球大气层中的湍流这一额外问题。湍流会使恒星闪烁，望远镜使用一种名为“自适应光学”的技术来消除这种闪烁。最后进行图像处理，找出噪声中的系外行星信号。目前的仪器不能成像最暗淡的行星，因为它们受到“斑点”的限制，这些斑点是由上述所有步骤中的缺陷造成的。然而，当前在分析此类图像时并未使用所有可用信息。几乎所有的图像处理方法都只使用科学图像本身。这就产生了许多偏见和伪像。尤其是在靠近恒星的地方，大多数行星都可以在那里找到。这个项目的目标是利用所有的综合信息发现更多的行星。将为现有的两台仪器编写软件，天文学家将使用它们来分析它们的图像。这个软件将被编写成易于使用，并向天文学家免费提供。学生将参与这两个参与机构。到目前为止，系外行星的直接成像特征仅限于距离恒星相对较远的年轻、热和大质量行星。这样的行星是可以观测到的，这是因为它们在形成后继续冷却时产生的内在自发光。如果可以改善内部工作角度，可以观测到更多的行星。此外，提高高对比度成像的灵敏度极限将使人们能够描述更暗、更小质量的行星。实现更灵敏的后处理的关键是使用现代高对比度成像系统中的一套波前传感器(WFS)同时记录的数据。这些包括主要的高阶WFS以及日冕图、低阶WFS和焦面WFS。研究人员将在博士后研究人员的协助下，基于现有的概念证明来实施算法，用实验室和星载数据测试和验证这些算法，并在Magao-X和SCExao仪器上部署软件系统。这两台Extreme-AO冠脉造影仪共享一个通用的软件框架，并且仪器团队之间存在协作。将部署这一系统，以便用户可以使用它来减少他们的数据，以便在较小的间隔时实现尽可能高的灵敏度。在当前一代的仪器上使用基于遥测的后处理系统将极大地提高它们的灵敏度。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。