Dark matter angular momentum profile from the jeans equation

Kasper B. Schmidt, Steen H. Hansen, Jin H. An, Liliya L.R. Williams, Andrea Maccio

Research output: Contribution to journalArticle

Abstract

Cosmological simulations of dark matter (DM) structures have shown that the equilibrated DM structures have a fairly small angular momentum. It appears from these N-body simulations that the radial profile of the angular momentum has an almost universal behavior, even if the different DM structures have experienced very different formation and merger histories. We suggest a perturbed Jeans equation, which includes a rotational term. This is done under a reasonable assumed form of the change in the distribution function. By conjecturing that the (new) subdominant rotation term must be proportional to the (old) dominant mass term, we find a clear connection, which is in rather good agreement with the results of recent high-resolution simulations. We also present a new connection between the radial profiles of the angular momentum and the velocity anisotropy, which is also in fair agreement with numerical findings. Finally, we show how the spin parameter λ increases as a function of radius.

Original languageEnglish (US)
Pages (from-to)893-901
Number of pages9
JournalAstrophysical Journal
Volume694
Issue number2
DOIs
StatePublished - Jan 1 2009

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angular momentum
dark matter
profiles
simulation
merger
anisotropy
distribution functions
histories
radii
high resolution
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distribution
parameter

Keywords

  • Dark matter
  • Galaxies: general
  • Galaxies: halos
  • Galaxies: kinematics and dynamics
  • Galaxies: structure
  • Methods: analytical

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Dark matter angular momentum profile from the jeans equation. / Schmidt, Kasper B.; Hansen, Steen H.; An, Jin H.; Williams, Liliya L.R.; Maccio, Andrea.

In: Astrophysical Journal, Vol. 694, No. 2, 01.01.2009, p. 893-901.

Research output: Contribution to journalArticle

Schmidt, Kasper B. ; Hansen, Steen H. ; An, Jin H. ; Williams, Liliya L.R. ; Maccio, Andrea. / Dark matter angular momentum profile from the jeans equation. In: Astrophysical Journal. 2009 ; Vol. 694, No. 2. pp. 893-901.
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