Bibcode
Sawala, T.; Frenk, Carlos S.; Fattahi, Azadeh; Navarro, Julio F.; Bower, Richard G.; Crain, Robert A.; Dalla-Vecchia, C.; Furlong, Michelle; Helly, John. C.; Jenkins, Adrian; Oman, Kyle A.; Schaller, Matthieu; Schaye, Joop; Theuns, Tom; Trayford, James; White, Simon D. M.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 457, Issue 2, p.1931-1943
Fecha de publicación:
4
2016
Número de citas
505
Número de citas referidas
469
Descripción
The Local Group galaxies offer some of the most discriminating tests of
models of cosmic structure formation. For example, observations of the
Milky Way (MW) and Andromeda satellite populations appear to be in
disagreement with N-body simulations of the `lambda cold dark matter'
(ΛCDM) model: there are far fewer satellite galaxies than
substructures in CDM haloes (the `missing satellites' problem); dwarf
galaxies seem to avoid the most massive substructures (the
`too-big-to-fail' problem); and the brightest satellites appear to orbit
their host galaxies on a thin plane (the `planes of satellites'
problem). Here we present results from APOSTLE (A Project Of Simulating
The Local Environment), a suite of cosmological hydrodynamic simulations
of 12 volumes selected to match the kinematics of the Local Group (LG)
members. Applying the EAGLE code to the LG environment, we find that our
simulations match the observed abundance of LG galaxies, including the
satellite galaxies of the MW and Andromeda. Due to changes to the
structure of haloes and the evolution in the LG environment, the
simulations reproduce the observed relation between stellar mass and
velocity dispersion of individual dwarf spheroidal galaxies without
necessitating the formation of cores in their dark matter profiles.
Satellite systems form with a range of spatial anisotropies, including
one similar to the MWs, confirming that such a configuration is not
unexpected in ΛCDM. Finally, based on the observed velocity
dispersion, size, and stellar mass, we provide estimates of the maximum
circular velocity for the haloes of nine MW dwarf spheroidals.