A Method to Characterize the Wide-angle Point-Spread Function of Astronomical Images
A Method to Characterize the Wide-angle Point-Spread Function of Astronomical Images
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一种表征天文图像广角点扩散函数的方法
DOI：
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发表时间：
2021
影响因子：
4.9
通讯作者：
J. Zhang 张
中科院分区：
文献类型：
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作者：
Q. Liu 刘;R. Abraham;C. Gilhuly;P. V. van Dokkum;P. Martin;J. Li 李;J. Greco;D. Lokhorst;Seery Chen;S. Danieli;M. Keim;A. Merritt;T. Miller;I. Pasha;Ava Polzin;Zili Shen;J. Zhang 张
大角度（数十角秒及以上）广角点扩展函数（PSF）的不确定性是天文观测中许多重要量误差的主要来源之一。例子包括恒星质量和星系晕的形状，以及附近星系盘上星光的最大范围。然而，广角PSF的建模一直是天文成像中的一个挑战。在本文中，我们提出了一种自洽方法来模拟图像中的广角PSF。来自多颗明亮恒星的散射光与背景模型同时拟合，使用逐像素水平的贝叶斯框架来表征PSF的扩展翼。该方法使用我们的软件elderflower进行了演示，并应用于蜻蜓远摄阵列的数据，以模拟其20 ‘ -25 ’范围内的PSF。我们将蜻蜓的广角PSF与包括SDSS PSF在内的许多其他望远镜的广角PSF进行了比较，结果表明，在弧分尺度上，蜻蜓PSF中的散射光明显低于其他宽视场成像望远镜。蜻蜓PSF机翼的能量足够低，光学清洁度在定义PSF时起着重要作用。PSF的这个组件可以精确地建模，突出了我们自包含方法的强大功能。
Uncertainty in the wide-angle point-spread function (PSF) at large angles (tens of arcseconds and beyond) is one of the dominant sources of error in a number of important quantities in observational astronomy. Examples include the stellar mass and shape of galactic halos and the maximum extent of starlight in the disks of nearby galaxies. However, modeling the wide-angle PSF has long been a challenge in astronomical imaging. In this paper, we present a self-consistent method to model the wide-angle PSF in images. Scattered light from multiple bright stars is fitted simultaneously with a background model to characterize the extended wing of the PSF using a Bayesian framework operating on a pixel-by-pixel level. The method is demonstrated using our software elderflower and is applied to data from the Dragonfly Telephoto Array to model its PSF out to 20′–25′. We compare the wide-angle PSF of Dragonfly to that of a number of other telescopes, including the SDSS PSF and show that, on scales of arcminutes, the scattered light in the Dragonfly PSF is markedly lower than that of other wide-field imaging telescopes. The energy in the wings of the Dragonfly PSF is sufficiently low that optical cleanliness plays an important role in defining the PSF. This component of the PSF can be modeled accurately, highlighting the power of our self-contained approach.
影响因子：
4.8
作者：
M. Jarvis;G. Bernstein;A. Amon;C. Davis;P. L'eget;K. Bechtol;I. Harrison;M. Gatti;A. Roodman
通讯作者：
M. Jarvis;G. Bernstein;A. Amon;C. Davis;P. L'eget;K. Bechtol;I. Harrison;M. Gatti;A. Roodman