Systematics in lensing reconstruction: dark matter rings in the sky?
Systematics in lensing reconstruction: dark matter rings in the sky?
复制标题
透镜重建的系统学：天空中暗物质环？
DOI：
--
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
J. Diego
中科院分区：
文献类型：
--
作者：
P. P. Ponente;J. Diego
上下文。非参数透镜方法是一种有用的方法，可以在不假设质量在星团中的分布方式的情况下重建星团的透镜质量。这些方法在具有大量约束的星系团的情况下特别有效。在星团处于非松弛动态状态的情况下，不隐含地假设发光物质跟随暗物质的优势特别有趣。另一方面，非参数方法有一些应该仔细考虑的限制。目标。我们探索了其中的一些限制，并重点研究了它们对CL0024+17星系团周围可能存在的暗物质环的影响。方法。我们通过已知径向轮廓密度的模拟星系团投射三个背景星系，并获得弧的映射（θ map）。我们还计算了整个视场中与模拟簇相关的剪切场（3.3 arcmin）。结合圆弧的位置和双向剪切，我们使用双共轭梯度和二次规划（QADP）两种不同的方法对透镜方程进行反演，以重建模拟簇的收敛映射。结果。我们探索了收敛映射解的空间，并将径向密度剖面与模拟簇的密度剖面进行了比较。当逆矩阵算法被迫寻找精确解时，我们会遇到类似环状结构的系统效应，这明显偏离了原始的收敛映射。结论。用非参数方法对透镜数据进行过拟合可以产生类似于CL0024中所谓的环状结构。
Context. Non-parametric lensing methods are a useful way of reconstructing the lensing mass of a cluster without making assumptions about the way the mass is distributed in the cluster. These methods are particularly powerful in the case of galaxy clusters with a large number of constraints. The advantage of not assuming implicitly that the luminous matter follows the dark matter is particularly interesting in those cases where the cluster is in a non-relaxed dynamical state. On the other hand, non-parametric methods have several limitations that should be taken into account carefully. Aims. We explore some of these limitations and focus on their implications for the possible ring of dark matter around the galaxy cluster CL0024+17. Methods. We project three background galaxies through a mock cluster of known radial profile density and obtain a map for the arcs (θ map). We also calculate the shear field associated with the mock cluster across the whole field of view (3.3 arcmin). Combining the positions of the arcs and the two-direction shear, we perform an inversion of the lens equation using two separate methods, the biconjugate gradient, and the quadratic programming (QADP) to reconstruct the convergence map of the mock cluster. Results. We explore the space of the solutions of the convergence map and compare the radial density profiles to the density profile of the mock cluster. When the inversion matrix algorithms are forced to find the exact solution, we encounter systematic effects resembling ring structures, that clearly depart from the original convergence map. Conclusions. Overfitting lensing data with a non-parametric method can produce ring-like structures similar to the alleged one in CL0024.
DOI：
10.1111/j.1365-2966.2006.10948.x
发表时间：
2006-05
影响因子：
4.8
作者：
A. Halkola;S. Seitz;M. Pannella
通讯作者：
A. Halkola;S. Seitz;M. Pannella
DOI：
10.1111/j.1365-2966.2010.18053.x
发表时间：
2010-11
期刊：
arXiv: Cosmology and Nongalactic Astrophysics
影响因子：
--
作者：
H. Hoekstra;J. Hartlap;S. Hilbert;E. V. Uitert
通讯作者：
H. Hoekstra;J. Hartlap;S. Hilbert;E. V. Uitert