COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses - X. Modeling based on high-precision astrometry of a sample of 25 lensed quasars: consequences for ellipticity, shear, and astrometric anomalies
COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses - X. Modeling based on high-precision astrometry of a sample of 25 lensed quasars: consequences for ellipticity, shear, and astrometric anomalies
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DOI：
10.1051/0004-6361/201015844
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发表时间：
2011-11
影响因子：
6.5
通讯作者：
D. Sluse;V. Chantry;P. Magain;F. Courbin;G. Meylan
中科院分区：
文献类型：
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作者：
D. Sluse;V. Chantry;P. Magain;F. Courbin;G. Meylan
引力透镜类星体可以用作强大的宇宙学和天体物理学探测器。我们可以(i)基于所谓的时间延迟技术推断哈勃常数H-0， （ii）揭示沿着视线指向遥远星系的子结构，（iii）比较星系内部区域重子和暗物质分布的形状和斜率。为了达到这些目标，我们需要相对于透镜星系的类星体图像的高精度天体测量和透镜的形态测量。本文首先对JVAS B0218+357、SBS 0909+532、RX J0911.4+0551、FBQS J0951+2635、HE 1104-1805、PG 1115+080、JVAS B1422+231、SBS 1520+530、CLASS B1600+434、CLASS B1608+656、HE 2149-2745等11个具有测量时间延迟的透镜提出了新的天体测量方法。这些测量是从使用magainm - courbin - sohy （MCS）反卷积算法（ISMCS）应用于近红外HST图像的迭代方式（ISMCS）开始的。我们获得了一个典型的天体测量精度约为1-2.5 mas和透镜星系的精确形状测量。其次，我们将这些测量结果与其他14个透镜系统的测量结果结合起来，其中大部分来自宇宙望远镜的目标集，以提出这些透镜的新质量模型。1)在4个双像类星体（HE0047-1746、J1226-006、SBS 1520+530和HE 2149-2745）中，我们发现透镜环境对时间延迟的影响可以很容易地量化和建模，因此将这些透镜作为确定时间延迟的优先级；2)对于四像类星体，通过在透镜模型中明确地包括最近的可见星系/卫星，克服了将图像位置复制到毫角秒精度的困难（天体测量异常问题）。然而，一个异常系统（RXS J1131-1231）在其附近没有显示任何发光扰动，另外三个系统（WFI 2026-4536， WFI 2033-4723和B2045+265）的建模存在问题。这四个系统是沿视距被暗物质子结构扰动的最佳候选者；3)重新研究了透镜星系中光的位置角（PA）与椭圆率和质量分布之间的关系。在以前的研究中，我们发现光的PA和质量分布之间有显著的相关性。然而，与这些相同的研究相比，我们发现光的椭圆度和质量的椭圆度也有很好的相关性，这表明物质的整体空间分布与内部的重子分布没有太大的不同，类似于透镜星系的5 kpc。这为高分辨率流体动力学模拟提供了一种新的测试方法。
Gravitationally lensed quasars can be used as powerful cosmological and astrophysical probes. We can (i) infer the Hubble constant H-0 based on the so-called time-delay technique, (ii) unveil substructures along the line-of-sight toward distant galaxies, and (iii) compare the shape and the slope of baryons and dark matter distributions in the inner regions of galaxies. To reach these goals, we need high-accuracy astrometry of the quasar images relative to the lensing galaxy and morphology measurements of the lens. In this work, we first present new astrometry for 11 lenses with measured time delays, namely, JVAS B0218+357, SBS 0909+532, RX J0911.4+0551, FBQS J0951+2635, HE 1104-1805, PG 1115+080, JVAS B1422+231, SBS 1520+530, CLASS B1600+434, CLASS B1608+656, and HE 2149-2745. These measurements proceed from the use of the Magain-Courbin-Sohy (MCS) deconvolution algorithm applied in an iterative way (ISMCS) to near-IR HST images. We obtain a typical astrometric accuracy of about 1-2.5 mas and an accurate shape measurement of the lens galaxy. Second, we combined these measurements with those of 14 other lensing systems, mostly from the COSMOGRAIL set of targets, to present new mass models of these lenses. The modeling of these 25 gravitational lenses led to the following results: 1) in four double-image quasars (HE0047-1746, J1226-006, SBS 1520+530, and HE 2149-2745), we show that the influence of the lens environment on the time delay can easily be quantified and modeled, hence putting these lenses with high priority for time-delay determination; 2) for quadruple-image quasars, the difficulty often encountered in reproducing the image positions to milli-arcsec accuracy (astrometric anomaly problem) is overcome by explicitly including the nearest visible galaxy/satellite in the lens model. However, one anomalous system (RXS J1131-1231) does not show any luminous perturber in its vicinity, and three others (WFI 2026-4536, WFI 2033-4723, and B2045+265) have problematic modeling. These four systems are the best candidates for a pertubation by a dark matter substructure along the line-of-sight; 3) we revisit the correlation between the position angle (PA) and ellipticity of the light and of the mass distribution in lensing galaxies. As in previous studies, we find a significant correlation between the PA of the light and of the mass distributions. However, in contrast with these same studies, we find that the ellipticity of the light and of the mass also correlate well, suggesting that the overall spatial distribution of matter is not very different from the baryon distribution in the inner similar to 5 kpc of lensing galaxies. This offers a new test for high-resolution hydrodynamical simulations.