利用多重成像星团“星座”进行与模型无关的引力透镜子结构探测
Model independent lensing sub-structure detection with multiply-imaged star clusters constellations
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中文总结 AI 辅助
本研究提出一种与模型无关的数据驱动超分辨引力透镜子结构探测方法，通过几何对偶技术，利用JWST观测的SMACS0723星系团中11个星团的成像数据进行验证，探测到一对可能对应$10^8-10^9\\,M_\odot$质量子晕的异常值。
中文摘要 AI 辅助
一大类暗物质（DM）模型预言，在无法分辨的角尺度上，暗物质晕中存在子结构。目前缺乏从衍射极限观测中提取这一普遍特征的技术。本研究提出一种与模型无关的“超分辨”方法，适用于强引力透镜系统，完全基于数据驱动，不依赖任何透镜模型。该方法依赖一种在成像数据多尺度上应用光学刘维尔定理的特定方式，我们称之为几何对偶技术。我们用真实模拟测试该方法，并将其应用于由詹姆斯·韦布空间望远镜（JWST）观测到的引力透镜星系团SMACS0723的两条巨弧中包含的11个致密星团组成的“星座”，作为概念验证。考虑统计灵敏度，我们发现结果与未探测的预期基本自洽，仅存在一对星团为异常值。在冷暗物质（CDM）框架下，该异常值可解释为质量范围为$M_{\rm sub}=10^8-10^9\\,M_\odot$的子晕产生的引力透镜，其对应的爱因斯坦半径小于JWST的衍射极限。
英文摘要
A broad class of dark matter (DM) models predicts the existence of sub-structures residing in DM haloes on sub-resolvable angular scales. Techniques to extract such a generic feature from diffraction-limited observations are lacking. In this work, we propose a model-independent 'super-resolving' method applicable to strong gravitational lens systems that is fully data-driven, without reference to any lens models. This method relies on a specific way of applying the optical Liouville theorem across multiple scales in the imaging data, a technique we refer to as geometrical-duality. We test this method using realistic simulations and apply it to a 'constellation' consists of 11 compact star clusters seen in two giant arcs in the lensing cluster SMACS0723 imaged by JWST as a proof-of-concept. We find reasonable self-consistency with the expectation of non-detection given the statistical sensitivity, except for one pair of star clusters. Such an outlier can be explained in the context of CDM as sub-haloes lensing in the mass range $M_{\rm sub} = 10^8 - 10^9\,M_\odot$, for which the corresponding Einstein radius is smaller than the diffraction limit of JWST.
