标题： 星系的外围能告诉我们关于暗物质什么信息？ 显示英文标题

标题： What can the outskirts of galaxies tell us about dark matter?

摘要： 深度观测星系边缘揭示了流、壳层和晕的微弱扩展恒星成分(ESCs)，这些是卫星星系潮汐破坏的幽灵遗迹。 我们使用冷暗物质(CDM)和温暗物质(WDM)模型中的宇宙学星系形成模拟，探讨暗物质模型如何影响ESCs的空间、运动学和轨道特性。 这些结果表明，在大银河半径处的球对称恒星质量密度在WDM模型中可以比CDM模型低多达10倍，反映了WDM模型中卫星星系数量被抑制的预期。 然而，在与观测限制相容的WDM模型中，这些差异要小得多，并且与我们在CDM模型中发现的系统间变化大小相当。 这表明仅依靠未解析的ESCs来对暗物质施加限制将具有挑战性。 显示英文摘要

摘要： Deep observations of galaxy outskirts reveal faint extended stellar components (ESCs) of streams, shells, and halos, which are ghostly remnants of the tidal disruption of satellite galaxies. We use cosmological galaxy formation simulations in Cold Dark Matter (CDM) and Warm Dark Matter (WDM) models to explore how the dark matter model influences the spatial, kinematic, and orbital properties of ESCs. These reveal that the spherically averaged stellar mass density at large galacto-centric radius can be depressed by up to a factor of 10 in WDM models relative to the CDM model, reflecting the anticipated suppressed abundance of satellite galaxies in WDM models. However, these differences are much smaller in WDM models that are compatible with observational limits, and are comparable in size to the system-to-system variation we find within the CDM model. This suggests that it will be challenging to place limits on dark matter using only the unresolved ESC.