Local Group Analogs in ΛCDM Cosmological Simulations

doi:10.3847/1538-4357/ab6986

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	Local Group Analogs in ΛCDM Cosmological Simulations
	Zhai,Meng 2,3; Guo,Qi 1,4; Zhao,Gang 1,2; Gu,Qing 1,4; Liu,Ang 5
刊名	The Astrophysical Journal
	2020-02-10
卷号	890 期号:1
关键词	Cold dark matter Local Group Cosmology
ISSN号	0004-637X
DOI	10.3847/1538-4357/ab6986
英文摘要	Abstract We use semi-analytic galaxy catalogs based on two high-resolution cosmological N-body simulations, Millennium-WMAP7 and Millennium-II, to investigate the formation of Local Group (LG) analogs. Unlike previous studies, we use the observed stellar masses to select the LG member (Milky Way (MW) and M31) analogs, and then impose constraints using the observed separation, isolation, and kinematics of the two main member galaxies. By comparing radial and low-ellipticity orbits between the MW and M31, we find higher tangential velocity results in higher total mass, which are 10 and 10 for radial and low-ellipticity orbits. The orbits also influence the individual mass distribution of MW and M31 analogs. For radial orbits, typical host halo masses of the MW and M31 are 10 and 10 for low-ellipticity orbits, the masses are 10 and 10 . The LG is located primarily in filaments with tails extending toward higher densities up to . The dark matter velocity anisotropy parameters β of both the MW and M31 analogs are close to zero in the center, increasing to 0.2–0.3 at 50–80 kpc and decreasing slowly outward. The slope is much flatter than computed from the MW satellites, and the amplitude is smaller than traced by halo stars. Values of β from different tracers agree at?～120 kpc where β?～?0.2. We also find that model predictions agree broadly with observations in the radial distribution and luminosity function of satellites around the MW and M31.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:0004-637X-890-1-AB6986
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/53965]
专题	中国科学院国家天文台
作者单位	1.University of Chinese Academy of Sciences, No. 19 A Yuquan Road, Beijing, 100049, People’s Republic of China 2.Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People's Republic of China; gzhao@nao.cas.cn 3.Chinese Academy of Sciences South America Center for Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People's Republic of China 4.Key Laboratory for Computational Astrophysics, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People's Republic of China; guoqi@nao.cas.cn 5.INAF Osservatorio Astrofisico di Arcetri, Largo E. Fermi, I-50125 Firenze, Italy
推荐引用方式 GB/T 7714	Zhai,Meng,Guo,Qi,Zhao,Gang,et al. Local Group Analogs in ΛCDM Cosmological Simulations[J]. The Astrophysical Journal,2020,890(1).
APA	Zhai,Meng,Guo,Qi,Zhao,Gang,Gu,Qing,&Liu,Ang.(2020).Local Group Analogs in ΛCDM Cosmological Simulations.The Astrophysical Journal,890(1).
MLA	Zhai,Meng,et al."Local Group Analogs in ΛCDM Cosmological Simulations".The Astrophysical Journal 890.1(2020).