Metallicity Gradients - Mass Dependency in Dwarf Elliptical Galaxies
  The formation and evolution of galaxies is imprinted on their stellar
population radial gradients. Two recent articles present conflicting results
concerning the mass dependence of the metallicity gradients for early-type
dwarf galaxies. On one side, Spolaor et al. show a tight positive correlation
between the total metallicity, Z/H and the mass. On the other side, in a
distinct sample, we do not find any trend involving Fe/H (Koleva et al.). In
order to investigate the origin of the discrepancy, we examine various factors
that may affect the determination of the gradients: namely the sky subtraction
and the signal-to-noise ratio. We conclude that our detection of gradients are
well above the possible analysis biases. Then, we measured the Mg/Fe relative
abundance profile and found moderate gradients. The derived Z/H gradients
scatter around -0.4 dex/r_e. The two samples contain the same types of objects
and the reason of the disagreement is still not understood.
  Based on observations made with ESO telescopes at La Silla Paranal
observatory under program ID076.B-0196.
