堆叠强透镜与弱透镜联合：改进测量红移$z\sim 0.5$处大质量早型星系的恒星与暗物质分布

中文摘要 AI 辅助

我们通过结合堆叠强透镜和弱透镜测量，对红移$0.4<z<0.6$处的大质量早型星系中的恒星和暗物质分布提出了一种新的测量方法。由斯巴鲁望远镜超超新星相机（Hyper Suprime-Cam）数据实现的堆叠弱透镜测量可延伸至小半径$0.013\\,\mathrm{Mpc}/h$，并与来自13个强透镜系统的堆叠封闭投影质量测量相结合。我们发现，加入强透镜约束改进了对恒星和暗物质分布的约束。中心暗物质轮廓被发现与标准Navarro-Frenk-White密度轮廓一致。恒星初始质量函数被发现是底重的。内部区域的总密度轮廓可以很好地用幂律密度轮廓描述，其斜率为$-1.96\pm 0.07$，这也能合理地解释直至$1\\,\mathrm{Mpc}/h$的弱透镜信号。堆叠弱透镜轮廓将内部质量片变换参数约束为$\lambda_{\mathrm{c}}=0.978\pm0.010$。我们的分析表明，堆叠强透镜和弱透镜的结合是研究星系中心密度轮廓的有力工具。

英文摘要

We present a new measurement of the stellar and dark matter distributions in massive early-type galaxies at redshift $0.4<z<0.6$ by combining stacked strong and weak lensing measurements. The stacked weak lensing measurements down to the small radius of $0.013\,\mathrm{Mpc}/h$ enabled by the Subaru Telescope Hyper Suprime-Cam data are combined with stacked enclosed projected mass measurements from 13 strong lens systems. We find that adding strong lensing constraints improves constraints on the stellar and dark matter distributions. The central dark matter profile is found to be consistent with the standard Navarro-Frenk-White density profile. The stellar initial mass function is found to be bottom-heavy. The total density profile in the inner region is described well by the power-law density profile with the slope of $-1.96\pm 0.07$, which can also explain weak lensing signals out to $1\,\mathrm{Mpc}/h$ reasonably well. The stacked weak lensing profile constrains an internal mass-sheet transformation parameter to $λ_{\mathrm{c}}=0.978\pm0.010$. Our analysis demonstrates that the combination of the stacked strong and weak lensing serves as a powerful tool for studying central density profiles of galaxies.

发表机构

• Department of Physics, Graduate School of Science, Chiba University（千叶大学理学研究科物理学系）
• Center for Frontier Science, Chiba University（千叶大学前沿科学中心）

机构由 AI 辅助整理，请以论文原文为准。

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9 pages, 5 figures