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The fate of substructures in cold dark matter haloes

Angulo, R.E.; Lacey, C.G.; Baugh, C.M.; Frenk, C.S.

The fate of substructures in cold dark matter haloes Thumbnail


R.E. Angulo


We use the Millennium Simulation, a large, high-resolution N-body simulation of the evolution of structure in a Λ cold dark matter cosmology, to study the properties and fate of substructures within a large sample of dark matter haloes. We find that the subhalo mass function departs significantly from a power law at the high-mass end. We also find that the radial and angular distributions of substructures depend on subhalo mass. In particular, high-mass subhaloes tend to be less radially concentrated and to have angular distributions closer to the direction perpendicular to the spin of the host halo than their less massive counterparts. We find that mergers between subhaloes occur. These tend to be between substructures that were already dynamically associated before accretion into the main halo. For subhaloes larger than 0.001 times the mass of the host halo, it is more likely that the subhalo will merge with the central or main subhalo than with another subhalo larger than itself. For lower masses, subhalo–subhalo mergers become equally likely to mergers with the main subhalo. Our results have implications for the variation of galaxy properties with environment and for the treatment of mergers in galaxy formation models.


Angulo, R., Lacey, C., Baugh, C., & Frenk, C. (2009). The fate of substructures in cold dark matter haloes. Monthly Notices of the Royal Astronomical Society, 399(2), 983-995.

Journal Article Type Article
Publication Date Oct 21, 2009
Deposit Date Jan 28, 2012
Publicly Available Date Feb 19, 2015
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 399
Issue 2
Pages 983-995
Keywords Galaxies: haloes, Galaxies: interactions, Cosmology: theory, Dark matter.


Published Journal Article (847 Kb)

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2009 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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