Bibcode
McCarthy, I. G.; Schaye, J.; Dalla Vecchia, C.; Furlong, M.; Crain, R. A.; Theuns, T.; Trayford, J.; Frenk, C. S.; Bower, R. G.; Schaller, M.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 452, Issue 1, p.343-355
Fecha de publicación:
9
2015
Número de citas
92
Número de citas referidas
87
Descripción
We use the `Evolution and assembly of galaxies and their environments'
(EAGLE) cosmological simulation to investigate the effect of baryons on
the density profiles of rich galaxy clusters. We focus on EAGLE clusters
with M200 > 1014 M⊙ of which we
have six examples. The central brightest cluster galaxies (BCGs) in the
simulation have steep stellar density profiles, ρ*(r)
∝ r-3. Stars dominate the mass density for r < 10
kpc, and, as a result, the total mass density profiles are steeper than
the Navarro-Frenk-White (NFW) profile, in remarkable agreement with
observations. The dark matter halo itself closely follows the NFW form
at all resolved radii (r ≳ 3.0 kpc). The EAGLE BCGs have similar
surface brightness and line-of-sight velocity dispersion profiles as the
BCGs in the sample of Newman et al., which have the most detailed
measurements currently available. After subtracting the contribution of
the stars to the central density, Newman et al. infer significantly
shallower slopes than the NFW value, in contradiction with the EAGLE
results. We discuss possible reasons for this discrepancy, and conclude
that an inconsistency between the kinematical model adopted by Newman et
al. for their BCGs, which assumes isotropic stellar orbits, and the
kinematical structure of the EAGLE BCGs, in which the orbital stellar
anisotropy varies with radius and tends to be radially biased, could
explain at least part of the discrepancy.
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