First detection of galaxy-galaxy-galaxy lensing in RCS. A new tool for studying the matter environme
First detection of galaxy-galaxy-galaxy lensing in RCS. A new tool for studying the matter environme
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DOI：
10.1051/0004-6361:20078197
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发表时间：
2007-06
影响因子：
6.5
通讯作者：
P. Simon;P. Watts;P. Schneider;H. Hoekstra;M. Gladders;H. Yee;B. Hsieh;H. Lin
中科院分区：
文献类型：
--
作者：
P. Simon;P. Watts;P. Schneider;H. Hoekstra;M. Gladders;H. Yee;B. Hsieh;H. Lin
上下文弱引力透镜效应，即引力潮汐场引起的星系图像的微小相干畸变，可以用来研究物质与星系分布之间的关系。目标。在这种情况下，弱透镜效应到目前为止只被用于考虑一个二阶相关函数，该函数将物质密度和星系数密度作为分离的函数。我们实现了两个新的，三阶相关函数，最近在文献中提出的，并将其应用到红色序列集群调查。作为一个步骤，在未来利用这些新的放大器，我们证明，这是可能的，即使与现有的数据，使三阶透镜相关性的显着测量。方法.我们开发了一个优化的相关函数的计算机代码。为了检验其可靠性，进行了一组涉及模拟剪切目录的测试。相关函数被转换为孔径统计，这使得容易测试剩余的系统的数据。为了进一步验证我们的测量的鲁棒性，当随机化源椭圆度时，信号消失。最后，将透镜效应信号与基于晕圈模型的粗略预测进行比较。结果在~$1^\prime$和~$$11^\prime $的角标度上，发现两个透镜位置和一个源椭圆率之间存在显著的三阶相关，讨论了这种相关函数作为研究星系对平均物质环境的一种新工具.将两个源的椭圆度和一个透镜位置关联起来，产生一个不太重要但仍然可以检测到的信号，其尺度为~$4 ^\prime $。这两个信号大致都在支持其宇宙学起源的理论所预期的范围内。
Context. The weak gravitational lensing effect, small coherent distortions of galaxy images by means of a gravitational tidal field, can be used to study the relation between the matter and galaxy distribution. Aims. In this context, weak lensing has so far only been used for considering a second-order correlation function that relates the matter density and galaxy number density as a function of separation. We implement two new, third-order correlation functions that have recently been suggested in the literature, and apply them to the Red-Sequence Cluster Survey. As a step towards exploiting these new correlators in the future, we demonstrate that it is possible, even with already existing data, to make significant measurements of third-order lensing correlations. Methods. We develop an optimised computer code for the correlation functions. To test its reliability a set of tests involving mock shear catalogues are performed. The correlation functions are transformed to aperture statistics, which allow easy tests for remaining systematics in the data. In order to further verify the robustness of our measurement, the signal is shown to vanish when randomising the source ellipticities. Finally, the lensing signal is compared to crude predictions based on the halo-model. Results. On angular scales between ~$1^\prime$ and ~$11^\prime$ a significant third-order correlation between two lens positions and one source ellipticity is found. We discuss this correlation function as a novel tool to study the average matter environment of pairs of galaxies. Correlating two source ellipticities and one lens position yields a less significant but nevertheless detectable signal on a scale of ~$4^\prime$. Both signals lie roughly within the range expected by theory which supports their cosmological origin.