利用UNIONS弱引力透镜数据测量红Mapper星系团中卫星星系次晕的质量
Measuring satellite galaxy subhalo masses in redMaPPer clusters with UNIONS weak lensing data
AI总结：
该研究利用UNIONS弱引力透镜数据，通过统计卫星星系过剩表面质量密度来研究星系团子晕潮汐剥离，测量次晕与恒星质量比，发现其与星系团中心半径呈正相关，证实了潮汐剥离等环境过程对卫星星系质量关系的影响。
AI中文摘要：
在这项工作中，我们展示了从紫外近红外光学北方巡天（UNIONS）获得的富星系团中卫星星系的星系-星系引力透镜信号。此类观测对于理解星系团环境中的暗物质晕物理和相互作用动力学至关重要。我们的目标是研究星系团子晕的潮汐剥离。理论预测表明，卫星星系落入星系团时，其暗物质晕会被剥离并分散到星系团的主晕中，而恒星质量相对保持完整。探测此现象的一个可靠方法是通过统计测量不同星系团中心距离处卫星星系的过剩表面质量密度。我们的结果揭示了一个显著的引力透镜信号，大量透镜-源对具有强大的统计能力。拟合过程中用于约束次晕质量的简单模型有效地再现了相关卫星中心距离处观测到的引力透镜信号。但在较大距离处，由于主星系团晕占主导，该模型缺乏准确拟合过剩表面密度的复杂性。我们测量了次晕与恒星质量比作为星系团中心半径的函数，发现有强烈的正趋势。这些结果证实了潮汐剥离或其他影响卫星星系恒星成分及其暗物质晕相对质量的环境过程。
英文摘要：
In this work, we present the observed galaxy-galaxy lensing signal of satellite galaxies in rich clusters obtained from the Ultraviolet Near-Infrared Optical Northern Survey (UNIONS). Such observations are crucial for understanding dark matter halo physics and interaction dynamics in the cluster environment. Our goal is to investigate the tidal stripping of cluster subhalos. Theoretical predictions, supported by recent studies, suggest that as satellite galaxies fall into clusters, their dark matter halos are stripped and dispersed into the cluster's main halo, while their stellar mass remains relatively intact. A robust method to probe this phenomenon is through statistical measurements of the excess surface mass density of satellite galaxies at different cluster-centric distances. Our results reveal a significant lensing signal, with strong statistical power from the large number of lens-source pairs. A simple model used in the fitting process to constrain subhalo masses effectively reproduces the observed lensing signal at relevant satellite-centric distances. However, it lacks the complexity to accurately fit the excess surface density at larger distances, where the host cluster halo dominates. We measure the subhalo-to-stellar mass ratio as a function of cluster-centric radius and find a strong positive trend. These results confirm tidal stripping or other environmental processes that impact the relative masses of a satellite galaxy's stellar component and its dark matter halo.
