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arXiv 1709.09758astro-ph.CO
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EasyCritics I:在宽视场巡天中强透镜星系群和星系团的有效探测

EasyCritics I: Efficient detection of strongly-lensing galaxy groups and clusters in wide-field surveys

Sebastian Stapelberg, Mauricio Carrasco, Matteo Maturi

摘要:

我们提出了EasyCritics,一种算法来检测强透镜组和集群在宽场调查,而不依赖于弧的直接识别。EasyCritics假设光跟踪质量,以便从视线中观测到的明亮红色早型星系的通量中预测临界曲线最可能的位置。这些星系的位置,红移和通量限制了理想的引力透镜潜力作为源红移的函数多达五个自由参数,这是校准的少数已知的镜头。从透镜势出发,EasyCritics推导出了一个给定的、有代表性的源红移的临界曲线。代码高度并行化,使用快速傅立叶方法,并可选地使用GPU加速,以有效地处理大型数据集。当使用$0.25''/\mathrm{px}$的像素分辨率时,在现代四核CPU上搜索$\smash{1 \, \mathrm{deg}^2}$视场需要不到1分钟。在EasyCritics系列论文的第一部分中,我们描述了主要的基本概念,并对加拿大-法国-夏威夷望远镜透镜巡天的数据进行了首次演示。我们表明,EasyCritics能够识别已知的组和集群规模的镜头,包括一个集群与两个巨大的弧候选人,以前错过了自动电弧探测器。

英文摘要:

We present EasyCritics, an algorithm to detect strongly-lensing groups and clusters in wide-field surveys without relying on a direct recognition of arcs. EasyCritics assumes that light traces mass in order to predict the most likely locations of critical curves from the observed fluxes of luminous red early-type galaxies in the line of sight. The positions, redshifts and fluxes of these galaxies constrain the idealized gravitational lensing potential as a function of source redshift up to five free parameters, which are calibrated on few known lenses. From the lensing potential, EasyCritics derives the critical curves for a given, representative source redshift. The code is highly parallelized, uses fast Fourier methods and, optionally, GPU acceleration in order to process large datasets efficiently. The search of a $\smash{1 \, \mathrm{deg}^2}$ field of view requires less than 1 minute on a modern quad-core CPU, when using a pixel resolution of $0.25''/\mathrm{px}$. In this first part of a paper series on EasyCritics, we describe the main underlying concepts and present a first demonstration on data from the Canada-France-Hawaii-Telescope Lensing Survey. We show that EasyCritics is able to identify known group- and cluster-scale lenses, including a cluster with two giant arc candidates that were previously missed by automated arc detectors.

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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