Parametric strong gravitational lensing analysis of Abell 1689
Parametric strong gravitational lensing analysis of Abell 1689
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DOI：
10.1111/j.1365-2966.2006.10948.x
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发表时间：
2006-05
影响因子：
4.8
通讯作者：
A. Halkola;S. Seitz;M. Pannella
中科院分区：
文献类型：
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作者：
A. Halkola;S. Seitz;M. Pannella
利用星系团阿贝尔1689对32个背景星系的强透镜效应，计算了该星系团中心0.3h-170 Mpc范围内的质量分布，共绘制了107幅多重图像.多个图像基于文献中的一些，并进行了修改，以包括新的和排除一些原始图像系统。利用文献中的弱透镜剪切测量，进一步研究了2.5h-170 Mpc的团簇分布.为了精确模拟星系团中的小尺度质量结构，用基本面法测量了2000个星系团的质量。团星系被模拟为椭圆形截断等温球。截断半径的标度与星系的速度色散被假定为匹配的：（i）场星系;和（ii）在稠密环境中的星系的理论期望。暗物质（DM）组成的集群被描述的非奇异等温椭球（NSIE）或椭圆版本的通用DM配置文件（椭圆纳瓦罗，弗伦克和白色，ENFW）。为了解释DM中的子结构，我们允许两个DM晕。非奇异等温球（NSIS）与光滑DM分量的拟合结果表明，速度频散为1450 + 39 - 31 km s-1，核半径为77 + 10 - 8h-170 kpc，而Navarro，Frenk &白色（NFW）曲线的r200为2.86 ± 0.16 h-1 70 Mpc（M200 = 3.2 × 10 15 M·h-70），浓度为4.7 ± 0.6-0.5。总质量分布可以用σ = 1514 + 18 - 17 kms-1，核半径rc = 71 ± 5 h-170 kpc的NSIS分布来描述;或NFW曲线C = 6.0 ± 0.5，r200 = 2.82 ± 0.11h-170 Mpc（M200 = 3.0 × 1015 M·h-70）。这些误差被认为是由于在分配质量的星系组成中的个别星系的错误。它们的小尺寸是由于多幅图像所施加的非常强的约束，以及平滑DM分量适应星系质量不确定性的能力。尽管所使用的方法有相当大的差异，但在所有半径处，这项工作与文献的总质量分布之间的一致性优于1σ。使用相同的图像配置中使用的文献中，我们得到的SL模型，上级一些文献中（均方根为2.7相比，3.2弧秒）。这是非常令人惊讶的考虑到更大的自由度，在他们的网格建模的表面质量轮廓。这种差异很可能是由于星系团星系被小心地包含在内的结果。利用文献中的WL剪切测量结果，我们可以进一步将剖面限制在r = 2.5h-170 Mpc。NSIS剖面的最佳拟合参数为a = 1499 ± 15 km s-1，rc = 66 ± 5 h-170 kpc; NFW剖面的最佳拟合参数为C = 7.6 ± 0.5，r200 = 2.55 ± 0.07h-170 Mpc（M200 = 2.3 × 1015 M·h-70）。
We have derived the mass distribution of galaxy cluster Abell 1689 within 0.3 h -1 70 Mpc of the cluster centre using its strong lensing (SL) effect on 32 background galaxies, which are mapped in altogether 107 multiple images. The multiple images are based on some from the literature with modifications to both include new and exclude some of the original image systems. The cluster profile is explored further out to ∼2.5 h -1 70 Mpc with weak lensing (WL) shear measurements from the literature. The masses of ∼200 cluster galaxies are measured with the Fundamental Plane (FP) in order to model accurately the small-scale mass structure in the cluster. The cluster galaxies are modelled as elliptical truncated isothermal spheres. The scalings of the truncation radii with the velocity dispersions of galaxies are assumed to match those of: (i) field galaxies; and (ii) theoretical expectations for galaxies in dense environments. The dark matter (DM) component of the cluster is described by either non-singular isothermal ellipsoids (NSIE) or elliptical versions of the universal DM profile (elliptical Navarro, Frenk & White, ENFW). To account for substructure in the DM we allow for two DM haloes. The fitting of a non-singular isothermal sphere (NSIS) to the smooth DM component results in a velocity dispersion of 1450 +39 -31 km s -1 and a core radius of 77 +10 -8 h -1 70 kpc, while a Navarro, Frenk & White (NFW) profile has an r 200 of 2.86 ± 0.16 h -1 70 Mpc (M 200 = 3.2 x 10 15 M ⊙ h 70 ) and a concentration of 4.7 +0.6 -0.5 . The total mass profile is well described by either a NSIS profile with σ = 1514 +18 -17 km s -1 and a core radius of r c = 71 ± 5 h -1 70 kpc, or an NFW profile with C = 6.0 ± 0.5 and r 200 = 2.82 ± 0.11 h -1 70 Mpc (M 200 = 3.0 x 10 15 M ⊙ h 70 ). The errors are assumed to be due to the error in assigning masses to the individual galaxies in the galaxy component. Their small size is due to the very strong constraints imposed by multiple images and the ability of the smooth DM component to adjust to uncertainties in the galaxy masses. The agreement in the total mass profile between this work and that of the literature is better than 1σ at all radii, despite the considerable differences in the methodology used. Using the same image configuration as used in the literature, we obtain a SL model that is superior to some in the literature (rms of 2.7 compared to 3.2 arcsec). This is very surprising considering the larger freedom in the surface mass profile in their grid modelling. The difference is most likely a result of the careful inclusion of the cluster galaxies. Using also WL shear measurements from the literature, we can constrain the profile further out to r ∼2.5 h -1 70 Mpc. The best-fitting parameters change to a = 1499 ± 15 km s -1 and r c = 66 ± 5 h -1 70 kpc for the NSIS profile and C = 7.6 ± 0.5 and r 200 = 2.55 ± 0.07 h -1 70 Mpc (M 200 = 2.3 x 10 15 M ⊙ h 70 ) for the NFW profile.