摘要: We rederive the number density of intervening line-of-sight haloes relative to lens subhaloes in galaxy-galaxy strong lensing observations, where these perturbers can generate detectable image fluctuations. Previous studies have calculated the detection limit of a line-of-sight small-mass dark halo by comparing the lensing deflection angles it would cause, to those caused by a subhalo within the lens. However, this overly simplifies the difference in observational consequences between a subhalo and a line-of-sight halo. Furthermore, it does not take into account degeneracies between an extra subhalo and the uncertain properties of the main lens. More in keeping with analyses of real-world observations, we regard a line-of-sight halo as detectable only if adding it to a smooth model generates a statistically significant improvement in the reconstructed image. We find that the number density of detectable line-of-sight perturbers has been overestimated by as much as a factor of two in the previous literature. For typical lensing geometries and configurations, very deep imaging is sensitive to twice as many line-of-sight perturbers as subhaloes, but moderate depth imaging is sensitive to only slightly more line-of-sight perturbers than subhaloes.
-
分类:
天文学
>>
星系和宇宙学
-
投稿状态:
已投稿期刊
-
引用:
ChinaXiv:202302.00235
(或此版本
ChinaXiv:202302.00235V1)
DOI:https://doi.org/10.48550/arXiv.2110.04512
CSTR:32003.36.ChinaXiv.202302.00235.V1
- 推荐引用方式:
Qiuhan He,Ran Li,Carlos S. Frenk,James Nightingale,Shaun Cole,Nicola C. Amorisco,Richard Massey,Andrew Robertson,Amy Etherington,Aristeidis Amvrosiadis,Xiaoyue Cao.(2023).Galaxy-galaxy strong lens perturbations: line-of-sight haloes versus lens subhaloes.中国科学院科技论文预发布平台.doi:https://doi.org/10.48550/arXiv.2110.04512
(点此复制)