Further evidence for a population of dark-matter-deficient dwarf galaxies
Further evidence for a population of dark-matter-deficient dwarf galaxies
复制标题
缺乏暗物质的矮星系群体的进一步证据
DOI：
10.1038/s41550-019-0930-9
复制
发表时间：
2020
期刊：
影响因子：
14.1
通讯作者：
Hong Wu
中科院分区：
文献类型：
--
作者：
Qi Guo;Huijie Hu;Zheng Zheng;Shihong Liao;Wei Du;Shude Mao;Linhua Jiang;Jing Wang;Yingjie Peng;Liang Gao;Jie Wang;Hong Wu
在标准宇宙学模型中，暗物质驱动星系的结构形成，并构造星系可能形成的势威尔斯。在大质量星系团中，暗晕中的重子分数可以达到普适值（15.7%），并随着系统质量的减小而迅速减小。矮星系的形成对重子过程和暗物质的性质都很敏感，因为它们形成于浅的威尔斯势阱中。在本星系群的矮星系中，暗物质甚至在它们的光-光半半径（Re = 1 kpc）内也占主导地位。然而，最近有人认为，并非所有的矮星系都是由暗物质主导的。在这里，我们报告了19个矮星系，它们可能主要由半径远大于drondre的重子组成，在这一点上，它们预计将被暗物质所主导。其中14个是孤立的矮星系，不受附近明亮星系和高密度环境的影响。这一结果提供了观测证据，可以挑战标准宇宙学框架内的低质量星系形成理论。需要进一步的观测，特别是深度成像和空间分辨运动学，以更好地约束这些星系中的重子分数。
In the standard cosmological model, dark matter drives the structure formation of galaxies and constructs potential wells within which galaxies may form. The baryon fraction in dark halos can reach the Universal value (15.7%) in massive clusters and decreases rapidly as the mass of the system decreases,. The formation of dwarf galaxies is sensitive both to baryonic processes and the properties of dark matter owing to the shallow potential wells in which they form. In dwarf galaxies in the Local Group, dark matter dominates the mass content even within their optical-light half-radii (re≈ 1 kpc),. However, recently it has been argued that not all dwarf galaxies are dominated by dark matter, –. Here we report 19 dwarf galaxies that could consist mainly of baryons up to radii well beyondre, at which point they are expected to be dominated by dark matter. Of these, 14 are isolated dwarf galaxies, free from the influence of nearby bright galaxies and high-density environments. This result provides observational evidence that could challenge the formation theory of low-mass galaxies within the framework of standard cosmology. Further observations, in particular deep imaging and spatially resolved kinematics, are needed to constrain the baryon fraction better in such galaxies.