Bibcode
La Barbera, F.; Pasquali, A.; Ferreras, I.; Gallazzi, A.; de Carvalho, R. R.; de la Rosa, I. G.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 445, Issue 2, p.1977-1996
Fecha de publicación:
12
2014
Número de citas
43
Número de citas referidas
41
Descripción
A detailed analysis of how environment affects the star formation
history of early-type galaxies (ETGs) is undertaken via high
signal-to-noise ratio stacked spectra obtained from a sample of 20 977
ETGs (morphologically selected) from the Sloan Digital Sky Survey-based
SPIDER survey. Two major parameters are considered for the study: the
central velocity dispersion (σ), which relates to local drivers of
star formation, and the mass of the host halo, which relates to
environment-related effects. In addition, we separate the sample between
centrals (the most massive galaxy in a halo) and satellites. We derive
trends of age, metallicity, and [α/Fe] enhancement, with σ.
We confirm that the major driver of stellar population properties in
ETGs is velocity dispersion, with a second-order effect associated with
the central/satellite nature of the galaxy. No environmental dependence
is detected for satellite ETGs, except at low σ - where satellites
in groups or in the outskirts of clusters tend to be younger than those
in the central regions of clusters. In contrast, the trends for centrals
show a significant dependence on halo mass. Central ETGs in groups (i.e.
with a halo mass >1012.5 M⊙) have younger
ages, lower [α/Fe], and higher internal reddening, than `isolated'
systems (i.e. centrals residing in low-mass, <1012.5
M⊙, haloes). Our findings imply that central ETGs in
groups formed their stellar component over longer time scales than
`isolated' centrals, mainly because of gas-rich interactions with their
companion galaxies.
Proyectos relacionados
Huellas de la Formación de las Galaxias: Poblaciones estelares, Dinámica y Morfología
Bienvenida a la página web del g rupo de investigación Traces of Galaxy Formation. Somos un grupo de investigación amplio, diverso y muy activo cuyo objetivo principal es entender la formación de galaxias en el Universo de una manera lo más completa posible. Con el estudio detellado de las poblaciones estelares como bandera, estamos constantemente
Ignacio
Martín Navarro