Strong-lensing optical depths in a ΛCDM universe -: II.: The influence of the stellar mass in galaxies
Strong-lensing optical depths in a ΛCDM universe -: II.: The influence of the stellar mass in galaxies
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DOI：
10.1111/j.1365-2966.2008.13190.x
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发表时间：
2008-06-01
影响因子：
4.8
通讯作者：
Schneider, Peter
中科院分区：
文献类型：
--
作者：
Hilbert, Stefan;White, Simon D. M.;Schneider, Peter
我们研究如何强引力透镜在和谐的Lambda CDM宇宙学的星系中的恒星质量的影响。我们扩展了我们以前的研究，通过千禧年模拟射线追踪的基础上，包括星系形成模型预测的恒星成分。我们发现，包含这些组件大大提高了强透镜的概率相比，“暗物质只有”的宇宙。与强透镜事件相关的“透镜”的识别表明，星系的恒星质量（i）显着增强了集团和集群晕的强透镜截面，（ii）在较小的晕中产生强透镜，这在没有恒星的情况下不会产生明显的影响。即使我们只考虑大于或近似于10弧秒的图像分裂，发光物质也可以将强透镜光学深度提高到2倍。
We investigate how strong gravitational lensing in the concordance Lambda CDM cosmology is affected by the stellar mass in galaxies. We extend our previous studies, based on ray tracing through the Millennium Simulation, by including the stellar components predicted by galaxy formation models. We find that the inclusion of these components greatly enhances the probability for strong lensing compared to a 'dark matter only' universe. The identification of the 'lenses' associated with strong-lensing events reveals that the stellar mass of galaxies (i) significantly enhances the strong-lensing cross-sections of group and cluster haloes and (ii) gives rise to strong lensing in smaller haloes, which would not produce noticeable effects in the absence of the stars. Even if we consider only image splittings greater than or similar to 10 arcsec, the luminous matter can enhance the strong-lensing optical depths by up to a factor of 2.