I present a complete spectroscopic analysis of a sample of massive (>10^11
M⨀) early-type galaxies (ETGs) in the redshift range 1.41.4 ETGs.
Spectroscopic data come from observations obtained with the X-Shooter
spectrograph at the VLT which covers with high spectral resolution the
spectral bands from the UV to the near IR. The observed wide spectral
window allows to perform for each individual target both a full-spectrum
fitting analysis to assign the properties of its stellar content (e.g.
age, metallicity and abundance ratios), as well as the velocity dispersion
estimate. Furthermore, we measure newly explored spectral indices in the
UV region (i.e.: MgI, MgII, Mgwide, etc...) in addition to the classical
optical Lick/IDS system (i.e.: Hβ, Mgb, etc..), which allow to fix the
stellar parameters in a more detailed and complementary way with respect
to the global fitting analysis.
We compare all the measurements with a large range of stellar population
synthesis models, exploring a large parameters space including also non
solar values of the chemical abundances. Such a comparison enables us to
get hints on the star formation histories of the galaxies sample, in
particular on their star formation time-scale within which this passive
objects have formed at least the bulk of their stars.
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