标题： 使用极大望远镜对类地行星成像 显示英文标题

标题： Imaging Earth-like planets with Extremely Large Telescopes

摘要： 我们研究了利用地基极大望远镜（ELT）结合自适应光学系统检测类地行星的可能性，这些系统能够在可见光和近红外波段提供高斯特尔比。 通过对残余光晕的斑点噪声进行详细分析，我们推导出在存在斑点噪声和残余恒星晕光子噪声的情况下，直接成像和差分成像的信噪比解析表达式。 我们发现，一台100米望远镜可以在10秒差距的距离上以5的信噪比检测到一颗类地行星，积分时间为12小时。 这要求仪器的像差控制精度优于1纳米rms，并达到在$1.2{\rm x}10^{6}$动态范围内的图像对比度，对应于$0\farcs 1$半径。 在相同条件下，一台30米望远镜需要达到$1.3{\rm x}10^{7}$的动态范围才能实现正向探测。 显示英文摘要

摘要： We investigate the possiblity to detect Earth-like planets, in the visible and the near infrared domains, with ground based Extremely Large Telescopes equipped with adaptive systems capable of providing high Strehl ratios. From a detailed analysis of the speckle noise, we derive analytical expressions of the signal to noise ratio on the planet flux, for direct and differential imaging, in the presence of the speckle noise and the photon noise of the residual stellar halo. We find that a 100m telescope would detect an Earth at a distance of 10pc, with a signal to noise ratio of 5, in an integration time of 12 hours. This requires to control the instrumental aberrations with a precision better than 1 nanometer rms, and to reach an image dynamics of $1.2{\rm x}10^{6}$ at $0\farcs 1$ radius. Under the same conditions, a telescope of 30m would require a dynamics of $1.3{\rm x}10^{7}$ for a positive detection