The Milky Way system in LCDM cosmological simulations

Abstract

We apply a semi-analytic galaxy formation model to two high resolution cosmological N-body simulations to investigate analogues of the Milky Way system. We select these according to observed properties of the Milky Way rather than by halo mass as in most previous work. For disk-dominated central galaxies with stellar mass (5--7) x 10d10Msun, the median host halo mass is 1.4 x 10d12Msun, with 1 sigma dispersion in the range [0.86, 3.1] x 10d12Msun, consistent with dynamical measurements of the Milky Way halo mass. For any given halo mass, the probability of hosting a Milky Way system is low, with a maximum of ~20% in haloes of mass ~10d12Msun. The model reproduces the V-band luminosity function and radial profile of the bright (MV < -9) Milky Way satellites. Galaxy formation in low mass haloes is found to be highly stochastic, resulting in an extremely large scatter in the relation between MV (or stellar mass) for satellites and the depth of the subhalo potential well in which they live, as measured by the maximum of the rotation curve, Vmax. We conclude that the "too big to fail" problem is an artifact of selecting satellites in N-body simulations according to subhalo properties: in 10% of cases we find that three or fewer of the brightest (or most massive) satellites have Vmax > 30 km/s. Our model predicts that around half of the dark matter subhaloes with Vmax > 20 km/s host satellites fainter than MV = -9 and so may be missing from existing surveys.

10 pages, 8 figures; submitted to MNRAS

References in corpus (16)

• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• The Milky Way's Circular Velocity Curve to 60 kpc and an Estimate of the Dark Matter Halo Mass from Kinematics of ~2400 SDSS Blue Horizontal Branch Stars
• Eight New Milky Way Companions Discovered in First-Year Dark Energy Survey Data
• Massloss of galaxies due to a UV-background
• A common mass scale for satellite galaxies of the Milky Way
• Hundreds of Milky Way Satellites? Luminosity Bias in the Satellite Luminosity Function
• The Tidal Evolution of Local Group Dwarf Spheroidals
• The Luminosity Function of the Milky Way Satellites
• Bent by baryons: the low mass galaxy-halo relation
• The Mass Profile of the Galaxy to 80 kpc
• The mass and velocity anisotropy of the Carina, Fornax, Sculptor and Sextans dwarf spheroidal galaxies
• Estimating the dark matter halo mass of our Milky Way using dynamical tracers
• M31 Satellite Masses Compared to LCDM Subhaloes
• Too Many, Too Few, or Just Right? The Predicted Number and Distribution of Milky Way Dwarf Galaxies
• Milky Way mass constraints from the Galactic satellite gap
• Subhalo statistics of galactic halos: beyond the resolution limit

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