Bibcode
Eliche-Moral, M. C.; Balcells, M.; Aguerri, J. A. L.; González-García, A. C.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 457, Issue 1, October I 2006, pp.91-108
Fecha de publicación:
10
2006
Revista
Número de citas
91
Número de citas referidas
80
Descripción
Context: .Satellite accretion events have been invoked for mimicking the
internal secular evolutionary processes of bulge growth. However, N-body
simulations of satellite accretions have paid little attention to the
evolution of bulge photometric parameters, to the processes driving this
evolution, and to the consistency of this evolution with observations.
Aims: .We want to investigate whether satellite accretions indeed
drive the growth of bulges, and whether they are consistent with global
scaling relations of bulges and discs. Methods: .We perform
N-body models of the accretion of satellites onto disc galaxies. A
Tully-Fisher (M∝ V_rotα_TF}) scaling between
primary and satellite ensures that density ratios, critical to the
outcome of the accretion, are realistic. We carry out a full structural,
kinematic and dynamical analysis of the evolution of the bulge mass,
bulge central concentration, and bulge-to-disc scaling relations.
Results: . The remnants of the accretion have bulge-disc structure. Both
the bulge-to-disc ratio (B/D) and the Sérsic index (n) of the
remnant bulge increase as a result of the accretion, with moderate final
bulge Sérsic indices: n = 1.0 to 1.9. Bulge growth occurs no
matter the fate of the secondary, which fully disrupts for α_TF=3
and partially survives to the remnant center for α_TF = 3.5 or 4.
Global structural parameters evolve following trends similar to
observations. We show that the dominant mechanism for bulge growth is
the inward flow of material from the disc to the bulge region during the
satellite decay. Conclusions: .The models confirm that the growth
of the bulge out of disc material, a central ingredient of secular
evolution models, may be triggered externally through satellite
accretion.