Determination of dark matter distribution in Ursa Major III and constraints on dark matter annihilation  

作　　者：Yi Zhao Xiao-Jun Bi Su-Jie Lin Peng-Fei Yin 赵熠;毕效军;林苏杰;殷鹏飞(College of Physics and Materials Science,Tianjin Normal University,Tianjin 300387,China;Key Laboratory of Particle Astrophysics,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;School of Physics and Astronomy,Sun Yat-Sen University,Zhuhai 519082,China)

机构地区：[1]College of Physics and Materials Science,Tianjin Normal University,Tianjin 300387,China [2]Key Laboratory of Particle Astrophysics,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China [3]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [4]School of Physics and Astronomy,Sun Yat-Sen University,Zhuhai 519082,China

出　　处：《Chinese Physics C》2024年第11期247-255,共9页中国物理C（英文版）

基　　金：Supported by the National Natural Science Foundation of China (11947005,12175248,12205388,12227804);the Science&Technology Development Fund of Tianjin Education Commission for Higher Education (2020KJ003);the PhD Research Startup Foundation of Tianjin Normal University (52XB1912)。

摘　　要：The recently discovered satellite dwarf galaxy Ursa Major III provides a promising opportunity to explore the signatures resulting from dark matter(DM)annihilation owing to its proximity and large J-factor.Given the absence of an excess ofγ-ray signatures originating from Ursa Major III,observations ofγ-rays,such as those from Fermi-LAT,can be utilized to set constraints on the DM annihilation cross-section.In this study,we determined the DM density profile and considered the relationship between DM density and velocity dispersion at different locations within Ursa Major III through Jeans analysis.We calculated the J-factor of Ursa Major III for s-wave annihilation along with the effective J-factors for p-wave and Sommerfeld enhanced annihilation scenarios.Employing these derived J-factors,we set stringent constraints on DM annihilation cross-sections in three scenarios.Given the substantial impact of member star identification on the J-factor of Ursa Major III,we further calculated J-factors under the exclusion of the largest velocity outlier.Our analysis reveals a notable reduction in the median value and an increase in the deviation of J-factors,thereby leading to considerably weaker constraints.

关 键 词：dark matter GAMMA-RAY dwarf spheroidal galaxy 

分 类 号：P145.9[天文地球—天体物理]