Gravitational lensing in WDM cosmologies: the cross-section for giant arcs
Gravitational lensing in WDM cosmologies: the cross-section for giant arcs
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DOI：
10.1093/mnras/stu705
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发表时间：
2014-04
影响因子：
4.8
通讯作者：
H. Mahdi;M. V. Beek;P. Elahi;G. Lewis;C. Power;M. Killedar
中科院分区：
文献类型：
--
作者：
H. Mahdi;M. V. Beek;P. Elahi;G. Lewis;C. Power;M. Killedar
宇宙暗区的性质仍然是现代宇宙学中突出的问题之一，寻找新的观测探测器指导下一代观测设施的发展。从CDM的预测和对引力透镜星系的观测之间的紧张关系中可以找到线索。先前的研究表明，CDM中的星系团不够强大，无法重现观测到的透镜弧数量。这项工作旨在通过从这些替代模型中得出的星系团的透镜效率来限制热暗物质宇宙学。研究了热暗物质（WDM）和冷暗物质（CDM）宇宙学中两个模拟星团样本的透镜特性。结果表明，尽管CDM簇更集中，包含更多的子结构，但WDM簇的透镜效率略高于CDM簇。关键的区别在于，与CDM类似物相比，WDM集群具有更多的扩展和更大的子晕。这些巨大的子结构显著地拉伸了临界线和焦散线，从而提高了主光晕的透镜效率。尽管由于WDM簇中大量子结构的贡献，透镜效率有所提高，但这还不足以解决电弧统计问题。
The nature of the dark sector of the Universe remains one of the outstanding problems in modern cosmology, with the search for new observational probes guiding the development of the next generation of observational facilities. Clues come from tension between the predictions from CDM and observations of gravitationally lensed galaxies. Previous studies showed that galaxy clusters in the CDM are not strong enough to reproduce the observed number of lensed arcs. This work aims to constrain the warm dark matter cosmologies by means of the lensing efficiency of galaxy clusters drawn from these alternative models. The lensing characteristics of two samples of simulated clusters in the warm dark matter ( WDM) and cold dark matter ( CDM) cosmologies have been studied. The results show that even though the CDM clusters are more centrally concentrated and contain more substructures, the WDM clusters have slightly higher lensing efficiency than their CDM counterparts. The key difference is that WDM clusters have more extended and more massive subhaloes than CDM analogues. These massive substructures significantly stretch the critical lines and caustics and hence they boost the lensing efficiency of the host halo. Despite the increase in the lensing efficiency due to the contribution of massive substructures in the WDM clusters, this is not enough to resolve the arc statistics problem.