The 5 Gyr evolution of sub-M* galaxies
  We gathered two complete samples of $M_{AB}(r)<-18$ ($M_{star} > 10^{9}
M_{\odot}$) galaxies, which are representative of the present-day galaxies and
their counterparts at 5 Gyr ago. We analysed their 2D luminosity profiles and
carefully decomposed them into bulges, bars and discs. This was done in a very
consistent way at the two epochs, by using the same image quality and same
(red) filters at rest. We classified them into elliptical, lenticular, spiral,
and peculiar galaxies on the basis of a morphological decision tree. We found
that at $z=0$, sub-M* ($10^{9} M_{\odot} < M_{star} < 1.5 \times 10^{10}
M_{\odot}$) galaxies follow a similar Hubble Sequence compared to their massive
counterparts, though with a considerable larger number of (1) peculiar galaxies
and (2) low surface brightness galaxies. These trends persist in the $z\sim0.5$
sample, suggesting that sub-M* galaxies have not reached yet a virialised
state, conversely to their more massive counterparts. The fraction of peculiar
galaxies is always high, consistent with a hierarchical scenario in which minor
mergers could have played a more important role for sub-M* galaxies than for
more massive galaxies. Interestingly, we also discovered that more than 10\% of
the sub-M* galaxies at z=0.5 are low surface brightness galaxies with clumpy
and perturbed features that suggest merging. Even more enigmatic is the fact
that their disc scale-lengths are comparable to that of M31, while their
stellar masses are similar to that of the LMC.
