Detalles de publicación
PP 021073
Surface Brightness Fluctuations to constrain secondary stellar populations: Revealing very low-metallicity stars in massive galaxies.
(1)Instituto de Astrofísica de Canarias (IAC),
(2) Departamento de Astrofísica Universidad de La Laguna
(3) Centro de Astrobiología (CSIC/INTA)
(4) Centro de Estudios de Física del Cosmos de Aragón
The aim of this work is to explore the potential of Surface Brightness Fluctuations (SBF) for studying composite stellar
populations (CSP). To do so, we have computed the standard (mean) and SBF spectra with E-MILES stellar population synthesis
code. We have created a set of models composed by different mass fractions of two single stellar populations (SSP), as a first
approximation of a CSP scenario. With these models we present an ensemble of SBF colour-colour diagnostic diagrams that
reveal different secondary populations depending on the bands used. For this work we focus on those colours capable of unveiling
small fractions of metal-poor components in elliptical galaxies, which are dominated by old metal-rich stellar populations. We
fit a set of synthetic models and a selection of nearby elliptical galaxies to our CSP models using both mean and SBF colours.
We find that the results are highly improved and return small secondary components when mean and SBF values are applied
simultaneously, instead of employing them separately or as a constraint. Finally, we explore the possibility of tracking chemical
enrichment histories by including in the analysis a variety of SBF colours. For this purpose we present an example where, with
two different SBF colour-colour diagrams, we untangle a small contribution of a young solar population and an old metal-poor
component from an old solar principal population. The results we have found are promising, but limited by the available data.
We highlight the urgent need for new, better and more consistent SBF observations.
populations (CSP). To do so, we have computed the standard (mean) and SBF spectra with E-MILES stellar population synthesis
code. We have created a set of models composed by different mass fractions of two single stellar populations (SSP), as a first
approximation of a CSP scenario. With these models we present an ensemble of SBF colour-colour diagnostic diagrams that
reveal different secondary populations depending on the bands used. For this work we focus on those colours capable of unveiling
small fractions of metal-poor components in elliptical galaxies, which are dominated by old metal-rich stellar populations. We
fit a set of synthetic models and a selection of nearby elliptical galaxies to our CSP models using both mean and SBF colours.
We find that the results are highly improved and return small secondary components when mean and SBF values are applied
simultaneously, instead of employing them separately or as a constraint. Finally, we explore the possibility of tracking chemical
enrichment histories by including in the analysis a variety of SBF colours. For this purpose we present an example where, with
two different SBF colour-colour diagrams, we untangle a small contribution of a young solar population and an old metal-poor
component from an old solar principal population. The results we have found are promising, but limited by the available data.
We highlight the urgent need for new, better and more consistent SBF observations.