TDCOSMO: XIV. Practical techniques for estimating external convergence of strong gravitational lens systems and applications to the SDSS J0924+0219 system
TDCOSMO: XIV. Practical techniques for estimating external convergence of strong gravitational lens systems and applications to the SDSS J0924+0219 system
复制标题
TDCOSMO：十四。
DOI：
10.1051/0004-6361/202346093
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发表时间：
2023
影响因子：
6.5
通讯作者：
Rusu, C. E.
中科院分区：
文献类型：
--
作者：
Wells, Patrick;Fassnacht, Christopher D.;Rusu, C. E.
时间延迟宇宙学使用强引力透镜的时间变量源来推断哈勃常数。该测量独立于传统的距离阶梯和CMB测量。使用该技术的精确测量需要考虑主透镜外部的物体沿着视线的影响，其由外部会聚（κext）量化。在没有这样的修正，H 0将偏向于高的值在过密领域和较低的值在underdense fields.AimsWe讨论的方法来考虑环境影响的现状。我们提出了一个新的软件包，为这种分析和其他可以利用大型天文调查数据集。我们将这些技术应用到SDSS J 0924 +0219强透镜field.MethodsWe推断的SDSS J 0924 +0219字段的相对密度计算加权数计数为所有星系在该领域，并比较加权数计数计算的大量领域中的参考调查。然后，我们计算加权数计数在千年模拟和比较这些结果来推断外部收敛的透镜field.ResultsOur结果显示，SDSS J 0924 +0219字段是一个相当典型的视线，中值κext=-0.012和标准差σκ= 0.028。
ContextTime-delay cosmography uses strong gravitational lensing of a time-variable source to infer the Hubble constant. The measurement is independent from both traditional distance ladder and CMB measurements. An accurate measurement with this technique requires considering the effects of objects along the line of sight outside the primary lens, which is quantified by the external convergence (κext). In absence of such corrections,H0will be biased towards higher values in overdense fields and lower values in underdense fields.AimsWe discuss the current state of the methods used to account for environment effects. We present a new software package built for this kind of analysis and others that can leverage large astronomical survey datasets. We apply these techniques to the SDSS J0924+0219 strong lens field.MethodsWe infer the relative density of the SDSS J0924+0219 field by computing weighted number counts for all galaxies in the field, and comparing to weighted number counts computed for a large number of fields in a reference survey. We then compute weighted number counts in the Millennium Simulation and compare these results to infer the external convergence of the lens field.ResultsOur results show the SDSS J0924+0219 field is a fairly typical line of sight, with medianκext= −0.012 and standard deviationσκ= 0.028.