Bibcode
Allende-Prieto, C.; Fernandez-Alvar, E.
Referencia bibliográfica
American Astronomical Society, AAS Meeting #223, #415.06
Advertised on:
1
2014
Número de citas
0
Número de citas referidas
0
Descripción
We still have a very limited knowledge about the formation of the early
Milky Way. A line of research has focused on understanding the nature of
the stellar halo, finding kinematical and chemical evidence of
substructure. The existence of substructure is in line with the
hierarchical formation scenario predicted by ΛCDM simulations for
large galaxies such as ours. Studies based on high resolution
spectroscopy have been limited to stars in the solar neighbourhood, and
their conclusions rely on correlations between kinematics and chemistry.
In this work, we have searched for halo stars in situ, using
mid-resolution ( 2000) spectra included in the SDSS/SEGUE survey for
stars at distances between 5 kpc and 100 kpc. We have analyzed a sample
of stars with effective temperatures in the range 5800 <
Teff < 6300 K, surface gravities between 0.0 < logg
< 5.0 dex and metallicities between -2.0 < [Fe/H] < -0.4 dex.
We have derived Ca/Fe and Mg/Fe abundance ratios from the spectra and
found clear correlations with metallicity and distance from the Galactic
center.