BULK FLOW OF HALOS IN Lambda CDM SIMULATION

	BULK FLOW OF HALOS IN Lambda CDM SIMULATION
	Li, Ming 1; Pan, Jun 2; Gao, Liang 2; Jing, Yipeng 3; Yang, Xiaohu 3; Chi, Xuebin 4; Feng, Longlong; Kang, Xi1 ; Lin, Weipeng 3; Shan, Guihua 4
刊名	ASTROPHYSICAL JOURNAL
	2012-12-20
卷号	761 期号:2
关键词	galaxies: halos large-scale structure of universe methods: statistical
英文摘要	Analysis of the Pangu N-body simulation validates that the bulk flow of halos follows a Maxwellian distribution with variance that is consistent with the prediction of the linear theory of structure formation. We propose that the consistency between the observed bulk velocity and theories should be examined at the effective scale of the radius of a spherical top-hat window function yielding the same smoothed velocity variance in linear theory as the sample window function does. We compared some recently estimated bulk flows from observational samples with the prediction of the Lambda CDM model we used; some results deviate from expectation at a level of similar to 3 sigma, but the discrepancy is not as severe as previously claimed. We show that bulk flow is only weakly correlated with the dipole of the internal mass distribution, that the alignment angle between the mass dipole and the bulk flow has a broad distribution peaked at similar to 30 degrees-50 degrees, and also that the bulk flow shows little dependence on the mass of the halos used in the estimation. In a simulation of box size 1 h(-1) Gpc, for a cell of radius 100 h(-1) Mpc the maximal bulk velocity is >500 km s(-1); dipoles of the environmental mass outside the cell are not tightly aligned with the bulk flow, but are rather located randomly around it with separation angles similar to 20 degrees-40 degrees. In the fastest cell there is a slightly smaller number of low-mass halos; however, halos inside are clustered more strongly at scales greater than or similar to 20 h(-1) Mpc, which might be a significant feature since the correlation between bulk flow and halo clustering actually increases in significance beyond such scales.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	PECULIAR VELOCITY-FIELD ; 100 H(-1) MPC ; IA SUPERNOVAE ; COSMIC FLOWS ; LOCAL UNIVERSE ; GALAXIES ; CLUSTERS ; DENSITY ; PREDICTION ; TELESCOPE
收录类别	SCI
语种	英语
WOS记录号	WOS:000312090300070
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/15556]
专题	紫金山天文台_南极天文中心
作者单位	1.Acad Sinica, Purple Mt Observ, Partner Grp MPI Astron, Nanjing 210008, Peoples R China 2.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 3.Shanghai Astron Observ, Key Lab Res Galaxies & Cosmol, Shanghai 200030, Peoples R China 4.Chinese Acad Sci, Comp Network Informat Ctr, Supercomp Ctr, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Li, Ming,Pan, Jun,Gao, Liang,et al. BULK FLOW OF HALOS IN Lambda CDM SIMULATION[J]. ASTROPHYSICAL JOURNAL,2012,761(2).
APA	Li, Ming.,Pan, Jun.,Gao, Liang.,Jing, Yipeng.,Yang, Xiaohu.,...&Zhang, Pengjie.(2012).BULK FLOW OF HALOS IN Lambda CDM SIMULATION.ASTROPHYSICAL JOURNAL,761(2).
MLA	Li, Ming,et al."BULK FLOW OF HALOS IN Lambda CDM SIMULATION".ASTROPHYSICAL JOURNAL 761.2(2012).