出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present the first results of intermediate resolution spectral observations in the CaII triplet
region obtained with VLT/FLAMES for 3 dwarf spheroidal galaxies in the Local Group: Sculptor,
Fornax and Sextans. For each galaxy, we obtained accurate velocity and metallicity measurements
for hundreds of stars out to and beyond the tidal radius: this was not possible with previous
observations. Therefore, with this work we are able to investigate the presence of gradients in the
kinematic and metallicity properties and explore possible links between them.
In each galaxy, we find clear evidence for the presence of two distinct stellar components with
different spatial distribution and kinematics: the metal rich component is more centrally concentrated
and kinematically colder than the metal poor one. These findings show that even dSphs,
the simplest galaxies known, have undergone a complex evolution.
