Star-Formation Bimodality in Early-Type Galaxies
  We compute the properties of a sample of 221 local early-type galaxies with a
spectral energy distribution (SED) modeling software, CIGALEMC. Concentrating
on the star forming activity and dust contents, we derive parameters such as
the specific star formation rate, the dust luminosity, dust mass and
temperature. 52 % of our sample is composed of elliptical (E) galaxies and 48 %
of lenticular (S0) galaxies. We find a larger proportion of S0 galaxies among
galaxies with a large specific star formation rate (sSFR) and large specific
dust emission. The stronger activity of S0 galaxies is confirmed by larger dust
masses. We investigate the relative proportion of active galactic nuclei (AGN)
and star-forming (SF) galaxies in our sample using spectroscopic SDSS data and
near-infrared selection techniques, and find a larger proportion of AGN
dominated galaxy in the S0 sample than the E one. This could corroborate a
scenario where blue galaxies evolve into red ellipticals by passing through a
S0 AGN active period while quenching its star formation. Finally, we find a
good agreement comparing our estimates with color indicators.
