Subhalo statistics of galactic haloes: beyond the resolution limit

Cautun, M.; Hellwing, W.A.; van de Weygaert, R.; Frenk, C.S.; Jones, B.J.T.; Sawala, T.

doi:10.1093/mnras/stu1829

Subhalo statistics of galactic haloes: beyond the resolution limit

Cautun, M.; Hellwing, W.A.; van de Weygaert, R.; Frenk, C.S.; Jones, B.J.T.; Sawala, T.

Authors

M. Cautun

W.A. Hellwing

R. van de Weygaert

C.S. Frenk

B.J.T. Jones

T. Sawala

Abstract

We study the substructure population of Milky Way (MW)-mass haloes in the Λ cold dark matter (ΛCDM) cosmology using a novel procedure to extrapolate subhalo number statistics beyond the resolution limit of N-body simulations. The technique recovers the mean and the variance of the subhalo abundance, but not its spatial distribution. It extends the dynamic range over which precise statistical predictions can be made by the equivalent of performing a simulation with 50 times higher resolution, at no additional computational cost. We apply this technique to MW-mass haloes, but it can easily be applied to haloes of any mass. We find up to 20 per cent more substructures in MW-mass haloes than found in previous studies. Our analysis lowers the mass of the MW halo required to accommodate the observation that the MW has only three satellites with a maximum circular velocity Vmax ≥ 30 km s− 1 in the ΛCDM cosmology. The probability of having a subhalo population similar to that in the MW is 20 per cent for a virial mass, M200 = 1 × 1012 M⊙ and practically zero for haloes more massive than M200 = 2 × 1012 M⊙.

Citation

Cautun, M., Hellwing, W., van de Weygaert, R., Frenk, C., Jones, B., & Sawala, T. (2014). Subhalo statistics of galactic haloes: beyond the resolution limit. Monthly Notices of the Royal Astronomical Society, 445(2), 1820-1835. https://doi.org/10.1093/mnras/stu1829

Journal Article Type	Article
Acceptance Date	Sep 4, 2014
Publication Date	Dec 1, 2014
Deposit Date	Oct 21, 2014
Publicly Available Date	Apr 15, 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	445
Issue	2
Pages	1820-1835
DOI	https://doi.org/10.1093/mnras/stu1829
Keywords	Galaxy: abundances, Galaxy: halo, Cosmology: theory, Dark matter.

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This article has been accepted for publication in Monthly notices of the Royal Astronomical Society. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.