The shape of dark matter haloes in the Aquarius simulations: Evolution and memory

C.A. Vera-Ciro, L. V. Sales, A. Helmi

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Samenvatting

We use the high resolution cosmological N-body simulations from the Aquarius project to investigate in detail the mechanisms that determine the shape of Milky Way-type dark matter haloes. We find that, when measured at the instantaneous virial radius, the shape of individual haloes changes with time, evolving from a typically prolate configuration at early stages to a more triaxial/oblate geometry at the present day. This evolution in halo shape correlates well with the distribution of the infalling material: prolate configurations arise when haloes are fed through narrow filaments, which characterizes the early epochs of halo assembly, whereas triaxial/oblate configurations result as the accretion turns more isotropic at later times. Interestingly, at redshift z = 0, clear imprints of the past history of each halo are recorded in their shapes at different radii, which also exhibit a variation from prolate in the inner regions to triaxial/oblate in the outskirts. Provided that the Aquarius haloes are fair representatives of Milky Way-like 1012Msun objects, we conclude that the shape of such dark matter haloes is a complex, time-dependent property, with each radial shell retaining memory of the conditions at the time of collapse.
Originele taal-2English
TitelAssembling the Puzzle of the Milky Way
SubtitelEPJ Web of Conferences
RedacteurenC Reyle, A Robin, M Schultheis
UitgeverijE D P SCIENCES
Aantal pagina's2
Volume19
ISBN van geprinte versie978-2-7598-0718-5
DOI's
StatusPublished - feb-2012
EvenementConferences of the Assembling the Puzzle of the Milky Way - , France
Duur: 17-apr-201122-apr-2011

Publicatie series

NaamEPJ Web of Conferences
UitgeverijE D P SCIENCES
Volume19
ISSN van geprinte versie2100-014X

Other

OtherConferences of the Assembling the Puzzle of the Milky Way
LandFrance
Periode17/04/201122/04/2011

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