科学家绘制局出部宇宙网,揭示暗物质地图揭示星系间隐藏的桥梁
科研圈
2021/06/04
论文
论文标题:Revealing the Local Cosmic Web from Galaxies by Deep Learning
作者:Sungwook E. Hong (???), Donghui Jeong, Ho Seong Hwang, and Juhan Kim
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期刊:The Astrophysical Journal
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日期:2021-05-26
数字识别码:10.3847/1538-4357/abf040
摘要:A total of 80% of the matter in the universe is in the form of dark matter that composes the skeleton of the large-scale structure called the cosmic web. As the cosmic web dictates the motion of all matter in galaxies and intergalactic media through gravity, knowing the distribution of dark matter is essential for studying the large-scale structure. However, the cosmic web's detailed structure is unknown because it is dominated by dark matter and warm–hot intergalactic media, both of which are hard to trace. Here we show that we can reconstruct the cosmic web from the galaxy distribution using the convolutional-neural-network-based deep-learning algorithm. We find the mapping between the position and velocity of galaxies and the cosmic web using the results of the state-of-the-art cosmological galaxy simulations of Illustris-TNG. We confirm the mapping by applying it to the EAGLE simulation. Finally, using the local galaxy sample from Cosmicflows-3, we find the dark matter map in the local universe. We anticipate that the local dark matter map will illuminate the studies of the nature of dark matter and the formation and evolution of the Local Group. High-resolution simulations and precise distance measurements to local galaxies will improve the accuracy of the dark matter map.
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所属学科:天文学
算法通过暗物质对星系(黑点)的引力影响,推断暗物质的位置,绘制其地图。不同方向截面的密度图再现了已知的宇宙特征(红色),也揭示了丝状特征(黄色),它们是星系之间的隐形桥梁。图中 X 代表银河系,箭头代表由于引力而引起的局域宇宙的运动。图片来源:Hong et. al., Astrophysical Journal
美国宾夕法尼亚州立大学(Pennsylvania State University)领导的国际天文学团队使用机器学习绘制了一张新的局域宇宙暗物质地图,揭示了一些先前未发现的连接星系的丝状结构。大尺度结构的宇宙物质结构被称为宇宙网,通过引力控制星系和星系间物质的运动。占宇宙物质总量约 80% 的暗物质是宇宙网的主要组成,因此暗物质研究与宇宙网研究密切相关。研究小组利用基于卷积神经网络的深度学习算法,通过星系分布重建了宇宙网,使用被称作 Illustris-TNG 的大量星系模拟结果,找到了星系位置和速度与宇宙网之间的映射关系,并通过 EAGLE 仿真验证了映射的正确性。最后,将模型应用于来自 Cosmicflow-3 数据库的局部星系样本数据,绘制出了局域宇宙中的暗物质图。该暗物质图包含了银河系附近超过 17000 个星系在 200 百万秒差距(约 6.5 亿光年)范围内的分布和运动的综合数据。该研究 5 月 26 日发表于《天体物理学杂志》(The Astrophysical Journal)。(Pennsylvania State University,The Astrophysical Journal)
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