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arXiv 1510.06331astro-ph.IMastro-ph.EP
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K-Stacker,一种用高对比度成像仪器探测和表征系外行星的新方法

K-Stacker, a new way of detecting and characterizing exoplanets with high contrast imaging instruments

H. Le Coroller, M. Nowak, L. Arnold, K. Dohlen, T. Fusco, J. F. Sauvage, A. Vigan

摘要:

今年,致力于对系外行星进行高对比度直接成像的第二代日冕仪开始运行。其中,安装在UT 3甚大望远镜焦点上的SPHERE采用极限自适应光学和角度差分成像技术,达到了前所未有的$10^{-6}$ - $ 10^{-7}$对比度。在本文中,我们提出了一种新的方法,称为开普勒堆栈,提高了高对比度仪器,如SPHERE的检测限,高达10倍。它包括观察一颗恒星足够长的时间,让一颗假设的行星绕着这颗恒星沿着它的轨道运动。即使在一个晚上进行的每个单独的观察中,我们没有检测到任何东西,我们表明,使用优化算法,根据开普勒运动(例如:在通常1-10年的长时间内拍摄的10-100张图像)重新定位图像并检测行星是可能的。该方法可以与ADI技术(或可能的任何其他高对比度数据减少方法)结合使用,以提高每个单独图像中的信噪比,并进一步提高全局检测限。它还直接提供了探测到的行星的轨道参数,作为优化算法的副产品。

英文摘要:

This year, a second generation of coronagraphs dedicated to high-contrast direct imaging of exoplanets is starting operations. Among them, SPHERE, installed at the focus of the UT3 Very Large Telescope, reaches unprecedented contrast ratios up to $10^{-6}$ -$ 10^{-7}$, using eXtreme Adaptive Optics and the Angular Differential Imaging (ADI) techniques. In this paper, we present a new method called Keplerian-Stacker that improves the detection limit of high contrast instruments like SPHERE, by up to a factor of 10. It consists of observing a star on a long enough period to let a hypothetical planet around that star move along its orbit. Even if in each individual observation taken during one night, we do not detect anything, we show that it is possible, using an optimization algorithm, to re-center the images according to keplerian motions (ex: 10-100 images taken over a long period of typically 1-10 years) and detect planets otherwise unreachable. This method can be used in combination with the ADI technics (or possibly any other high contrast data reduction method) to improve the Signal to Noise Ratio in each individual image, and to further improve the global detection limit. It also directly provides orbital parameters of the detected planets, as a by-product of the optimization algorithm.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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