Bibcode
Theuns, Tom; McCarthy, I. G.; Schaller, Matthieu; Frenk, Carlos S.; Furlong, Michelle; Dalla Vecchia, C.; van Daalen, Marcel P.; Bower, Richard G.; Crain, Robert A.; Schaye, Joop; Cacciato, Marcello; Velliscig, M.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 453, Issue 1, p.721-738
Fecha de publicación:
10
2015
Número de citas
122
Número de citas referidas
113
Descripción
We report the alignment and shape of dark matter, stellar, and hot gas
distributions in the EAGLE (Evolution and Assembly of GaLaxies and their
Environments) and cosmo-OWLS (OverWhelmingly Large Simulations)
simulations. The combination of these state-of-the-art hydrodynamical
cosmological simulations enables us to span four orders of magnitude in
halo mass (11 ≤ log10(M200/[ h-1
M⊙]) ≤ 15), a wide radial range (-2.3 ≤
log10(r/[ h-1 Mpc]) ≤ 1.3) and redshifts 0 ≤
z ≤ 1. The shape parameters of the dark matter, stellar and hot gas
distributions follow qualitatively similar trends: they become more
aspherical (and triaxial) with increasing halo mass, radius, and
redshift. We measure the misalignment of the baryonic components (hot
gas and stars) of galaxies with their host halo as a function of halo
mass, radius, redshift, and galaxy type (centrals versus satellites and
early- versus late-type). Overall, galaxies align well with the local
distribution of the total (mostly dark) matter. However, the stellar
distributions on galactic scales exhibit a median misalignment of about
45-50 deg with respect to their host haloes. This misalignment is
reduced to 25-30 deg in the most massive haloes (13 ≤
log10(M200/[ h-1 M⊙])
≤ 15). Half of the disc galaxies in the EAGLE simulations have a
misalignment angle with respect to their host haloes larger than 40 deg.
We present fitting functions and tabulated values for the probability
distribution of galaxy-halo misalignment to enable a straightforward
inclusion of our results into models of galaxy formations based on
purely collisionless N-body simulations.
Proyectos relacionados
Astrofísica Numérica: Formación y Evolución de Galaxias
Entre las cuestiones fundamentales en Astronomía y Astrofísica están la formación y evolución de galaxias. Las escalas de tiempo y tamaño son tan astronómicas que su observación en galaxias individuales es imposible. Solo con el uso de simulaciones numéricas es posible entender la formación de estructuras cósmicas dentro del actual marco
Claudio
Dalla Vecchia