Analyzing Deep Imaging Data: State of the art algorithms for weak lensing and galaxy formation

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)提供资金的。施特劳斯博士和他的团队将开发一种软件流水线，以系统的方式分析来自大型天文观测的图像，以优化它们在弱透镜测量中的使用：来自遥远星系的光在进入我们的望远镜的途中会受到所有物质的引力的弯曲，从而扭曲我们所看到的星系的形状。该软件将表征望远镜的点扩散函数及其在观察场中的变化，并以自洽和统计严格的方式分析给定场的多次曝光。该团队将改进对观察到的透镜状星系形状的测量，并试验表征其内在形状的方法。他们将把他们的代码应用于加拿大-法国-夏威夷遗产调查的原始数据，该调查现已公开。他们对弱透镜信号的测量(表明质量在最大尺度上聚集的强度)将给出完全独立于调查小组的结果。这些数据将使人们能够研究红移为1左右的星系属性，这些红移被视为宇宙扩张到现在大小的一半时的状态，其精度与斯隆数字巡天红移仅为十分之一时的精度大致相同。博士后学者将通过参与这项研究进行培训。校准后的光度星表将公之于众，包括详细的形状测量和光度红移。这些软件工具也将公之于众。这些和获得的见解都将适用于下一代广角调查，该调查的目标也是测量微弱的透镜信号。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Dr Strauss and his team will develop a software pipeline to analyze images from large sky surveys in a systematic way to optimize their use for weak-lensing measurements: light from a distant galaxy is bent by the gravity of all the matter that it passes by on its way to our telescopes, distorting the shape of the galaxy as we see it. The software will characterize the point spread function of the telescope and its variation across the observed field, and analyze multiple exposures of a given field in a self-consistent and statistically rigorous way. The team will both improve measurements of the observed shapes of the 'lensed' galaxies, and experiment with methods to characterize their intrinsic shapes. They will apply their code to raw data from the Canada-France-Hawaii Legacy Survey, which is now public. Their measurement of the weak-lensing signal (an indication of how strongly mass is clumped on the largest scales) will give results completely independent from those of that survey team. These data will enable the study of galaxy properties at redshifts around one, which are seen as they were when the cosmos had expanded to only half its present size, with roughly the same precision as that available at redshifts of only a tenth from the Sloan Digital Sky Survey.A postdoctoral scholar will be trained by participating in the research. The calibrated photometric catalogs will be made public, with the detailed shape measurements and photometric redshifts. The software tools will also be made public. Both those and the insights gained will be applicable to the next generation of wide-angle surveys, which also aim to measure weak-lensing signals.