藉由重力透鏡研究暗物質之結構

Abstract

揭曉暗物質 (dark matter, DM) 的本質在現代宇宙學中是非常重要的 課題。分折暗物質的結構更是對於星系生成及演化和大尺度結構非常 的關鍵。為了完成這個目標，我們同時使用宇宙數值模擬和天文觀測 資料。特別的是，我們使用重力透鏡效應 (grivatational lensing) 去探索 宇宙的黑暗成份。我們發表一套新的工具，CHITAH，去偵測影像巡 天觀測中的重力透鏡系統。CHITAH 已經在超廣角可見光相機巡天計 畫中 (the HSC survey) 尋找到數個有公信力的系統，並有計劃進行後續 觀測。在模擬部份，我們發表了一段有效演化波暗物質 (ψDM) 和星粒 子的工具。我們發現星系中的孤粒子核 (soliton) 會因為星粒子的重力 而吸收約二倍的質量，並滿足比例關係。在未來，使用類星體重力透 鏡系統和宇宙模擬能使我們證實/推翻波暗物質的模型。

Unveiling the nature of dark matter has become the golden question in modern cosmology, and understanding the structure/sub-structure of dark mat- ter in the Universe is important for our understanding of the formation/evolution of galaxies and large-scale structures. To achieve this goal, we conduct both cosmological simulations and astrophysical observations. In particular, we exploit a direct technique, gravitational lensing, to explore the dark side of the Universe. We present a novel algorithm, CHITAH, to classify lens systems in imaging surveys. CHITAH has classified a few promising lens candidates in the Hyper-Surprime Cam (HSC) survey, including lensed quasars and lensed galaxies with follow-up observations planned. In the simulation regime, we present an efficient algorithm for wave-like dark matter (ψDM) model plus stars. We discover that a solitonic core can absorb mass by a factor of 2 from its host halo to satisfy the scaling relation even in the presence of additional star gravity. Using lensed quasars and comparing with simulation results will allow us confirm/disconfirm ψDM model.