Coincidence between morphology and star-formation activity through
  cosmic time: the impact of the bulge growth
  The origin of the quenching in galaxies is still highly debated. Different
scenarios and processes are proposed. We use multi-band (400-1600 nm)
bulge-disc decompositions of massive galaxies in the redshift range 0<z<2 to
explore the distribution and the evolution of galaxies in the log SFR-logM*
plane as a function of the stellar mass-weighted bulge-to-total ratio (BTM) and
also for internal galaxy components (bulge/disc) separately. We find evidence
of a clear link between the presence of a bulge and the flattening of the Main
Sequence in the high-mass end. All bulgeless galaxies (BTM<0.2) lie on the
main-sequence, and there is little evidence of a quenching channel without
bulge growth. Galaxies with a significant bulge component (BTM>0.2) are equally
distributed in number between star forming and passive regions. The vast
majority of bulges in the Main Sequence galaxies are quiescent, while star
formation is localized in the disc component. Our current findings underline a
strong correlation between the presence of the bulge and the star formation
state of the galaxy. A bulge, if present, is often quiescent, independently of
the morphology or the star formation activity of the host galaxy. Additionally,
if a galaxy is quiescent, with a large probability, is hosting a bulge.
Conversely, if the galaxy has a disky shape is highly probable to be star
forming.
