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BULK FLOW OF HALOS IN Lambda CDM SIMULATION | |
Li, Ming1; Pan, Jun2; Gao, Liang2; Jing, Yipeng3; Yang, Xiaohu3; Chi, Xuebin4; Feng, Longlong![]() ![]() | |
2012-12-20 | |
Source Publication | ASTROPHYSICAL JOURNAL
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Volume | 761Issue:2 |
Abstract | 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. |
Keyword | Galaxies: Halos Large-scale Structure Of Universe Methods: Statistical |
WOS Headings | Science & Technology ; Physical Sciences |
DOI | 10.1088/0004-637X/761/2/151 |
WOS Keyword | PECULIAR VELOCITY-FIELD ; 100 H(-1) MPC ; IA SUPERNOVAE ; COSMIC FLOWS ; LOCAL UNIVERSE ; GALAXIES ; CLUSTERS ; DENSITY ; PREDICTION ; TELESCOPE |
Indexed By | SCI |
Language | 英语 |
WOS Research Area | Astronomy & Astrophysics |
WOS Subject | Astronomy & Astrophysics |
WOS ID | WOS:000312090300070 |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://libir.pmo.ac.cn/handle/332002/15586 |
Collection | 南极天文中心 |
Affiliation | 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 |
Recommended Citation 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). |
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