Cautun, M. and Hellwing, W. A. and van de Weygaert, R. and Frenk, C. S. and Jones, B. J. T. and Sawala, T. (2014) 'Subhalo statistics of galactic haloes : beyond the resolution limit.', Monthly notices of the Royal Astronomical Society., 445 (2). pp. 1820-1835.
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⊙.
|Keywords:||Galaxy: abundances, Galaxy: halo, Cosmology: theory, Dark matter.|
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|Publisher Web site:||http://dx.doi.org/10.1093/mnras/stu1829|
|Publisher statement:||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.|
|Record Created:||13 Apr 2015 14:50|
|Last Modified:||01 Jun 2015 09:26|
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