  Exploiting the deep high-resolution imaging of all 5 CANDELS fields, and
accurate redshift information provided by 3D-HST, we investigate the relation
between structure and stellar populations for a mass-selected sample of 6764
galaxies above 10^10 Msun, spanning the redshift range 0.5 < z < 2.5. For the
first time, we fit 2-dimensional models comprising a single Sersic fit and
two-component (i.e., bulge + disk) decompositions not only to the H-band light
distributions, but also to the stellar mass maps reconstructed from resolved
stellar population modeling. We confirm that the increased bulge prominence
among quiescent galaxies, as reported previously based on rest-optical
observations, remains in place when considering the distributions of stellar
mass. Moreover, we observe an increase of the typical Sersic index and
bulge-to-total ratio (with median B/T reaching 40-50%) among star-forming
galaxies above 10^11 Msun. Given that quenching for these most massive systems
is likely to be imminent, our findings suggest that significant bulge growth
precedes a departure from the star-forming main sequence. We demonstrate that
the bulge mass (and ideally knowledge of the bulge and total mass) is a more
reliable predictor of the star-forming versus quiescent state of a galaxy than
the total stellar mass. The same trends are predicted by the state-of-the-art
semi-analytic model by Somerville et al. In the latter, bulges and black holes
grow hand in hand through merging and/or disk instabilities, and AGN-feedback
shuts off star formation. Further observations will be required to pin down
star formation quenching mechanisms, but our results imply they must be
internal to the galaxies and closely associated with bulge growth.
