Nonparametric Reconstruction of Abell 2218 from Combined Weak and Strong Lensing
Nonparametric Reconstruction of Abell 2218 from Combined Weak and Strong Lensing
复制标题
利用弱透镜和强透镜组合非参数重建 Abell 2218
DOI：
--
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
L. Williams
中科院分区：
文献类型：
--
作者：
H. Abdelsalam;P. Saha;L. Williams
我们应用一种新的非参数技术来重建具有不确定性的Abell 2218内部区域的投影质量分布，使用来自多个图像系统和具有已知红移的拱形的强和弱透镜组合约束。重建的质量图与以前不太详细的参数模型大体相似，但当详细检查时，它显示了几个不一定与光相关的子结构，但透镜数据强烈需要它们。特别是，最高的质量峰被∼30hkpc从主光峰偏移，不同星系团星系方向的投影质光比至少相差10倍。与X射线发射气体模型的质量估计相比较，我们发现X射线模型对封闭质量剖面的预测至少低了2.5倍；如果我们假设质量跟踪光到透镜约束允许的程度，差异会变得更大。
We apply a new nonparametric technique to reconstruct, with uncertainties, the projected mass distribution of the inner region of Abell 2218 using combined strong and weak lensing constraints from multiple-image systems and arclets with known redshifts. The reconstructed mass map broadly resembles previous, less detailed parametric models, but when examined in detail it shows several substructures not necessarily associated with light but strongly required by the lensing data. In particular, the highest mass peak is offset by ∼30 h kpc from the main light peak, and projected mass-to-light ratio in the directions of different cluster galaxies varies by at least a factor of 10. On comparison with mass estimates from models of the X-ray emitting gas, we find that the X-ray models underpredict the enclosed mass profile by at least a factor of 2.5; the discrepancy gets worse if we assume that mass traces light to the extent allowed by the lensing constraints.