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The distribution of ejected subhaloes and its implication for halo assembly bias.

Authors :
Wang, Huiyuan
Mo, H. J.
Jing, Y. P.
Source :
Monthly Notices of the Royal Astronomical Society. Jul2009, Vol. 396 Issue 4, p2249-2256. 8p. 1 Chart, 9 Graphs.
Publication Year :
2009

Abstract

Using a high-resolution cosmological N-body simulation, we identify the ejected population of subhaloes, which are haloes at redshift but were once contained in more massive ‘host’ haloes at high redshifts. The fraction of the ejected subhaloes in the total halo population of the same mass ranges from 9 to 4 per cent for halo masses from to . Most of the ejected subhaloes are distributed within four times the virial radius of their hosts. These ejected subhaloes have distinct velocity distribution around their hosts in comparison to normal haloes. The number of subhaloes ejected from a host of given mass increases with the assembly redshift of the host. Ejected subhaloes in general reside in high-density regions, and have a much higher bias parameter than normal haloes of the same mass. They also have earlier assembly times, so that they contribute to the assembly bias of dark matter haloes seen in cosmological simulations. However, the assembly bias is not dominated by the ejected population, indicating that large-scale environmental effects on normal haloes are the main source for the assembly bias. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00358711
Volume :
396
Issue :
4
Database :
Academic Search Index
Journal :
Monthly Notices of the Royal Astronomical Society
Publication Type :
Academic Journal
Accession number :
42874565
Full Text :
https://doi.org/10.1111/j.1365-2966.2009.14884.x