Results of the GREAT08 Challenge: an image analysis competition for cosmological lensing
Results of the GREAT08 Challenge: an image analysis competition for cosmological lensing
复制标题
DOI：
10.1111/j.1365-2966.2010.16598.x
复制
发表时间：
2010-07-01
影响因子：
4.8
通讯作者：
Wittman, David
中科院分区：
文献类型：
--
作者：
Bridle, Sarah;Balan, Sreekumar T.;Wittman, David
我们给出了2008年引力透镜精度测试(GREAT08)挑战赛的结果，这是一项从图像中推断弱引力透镜剪切扭曲的盲目分析挑战。主要目标是通过向剪切测量社区以外的研究人员展示问题来激发新的想法。在挑战赛的启动仪式上展示了六种GREAT08团队方法，另外五个小组在为期六个月的比赛中提交了结果。参与者分析了3000万个模拟星系，这些星系的信噪比、点扩展函数椭圆度、星系大小和星系类型都有不同的范围。大量的模拟使剪切测量方法第一次能够以适合目前计划的未来宇宙剪切观测的精度水平进行评估。不同的方法在模拟参数空间的不同部分表现良好，并且在其中的几个方面接近目标精度水平。这次挑战的结果是出现了一些新的想法，包括重新检查合并来自不同星系的信息的过程，这减少了对真实星系模型的依赖。在未来的巨大挑战中，图像模拟将变得越来越复杂，同时GREAT08模拟仍然是剪切测量算法进一步开发的基准。
We present the results of the Gravitational LEnsing Accuracy Testing 2008 (GREAT08) Challenge, a blind analysis challenge to infer weak gravitational lensing shear distortions from images. The primary goal was to stimulate new ideas by presenting the problem to researchers outside the shear measurement community. Six GREAT08 Team methods were presented at the launch of the Challenge and five additional groups submitted results during the 6-month competition. Participants analyzed 30 million simulated galaxies with a range in signal-to-noise ratio, point spread function ellipticity, galaxy size and galaxy type. The large quantity of simulations allowed shear measurement methods to be assessed at a level of accuracy suitable for currently planned future cosmic shear observations for the first time. Different methods perform well in different parts of simulation parameter space and come close to the target level of accuracy in several of these. A number of fresh ideas have emerged as a result of the Challenge including a re-examination of the process of combining information from different galaxies, which reduces the dependence on realistic galaxy modelling. The image simulations will become increasingly sophisticated in future GREAT Challenges, meanwhile the GREAT08 simulations remain as a benchmark for additional developments in shear measurement algorithms.