Morphology and structure of BzK-selected galaxies at z~2 in the
  CANDELS-COSMOS field
  Utilizing a BzK-selected technique, we obtain 14550 star-forming galaxies
(sBzKs) and 1763 passive galaxies (pBzKs) at z~2 from the K-selected (K<22.5)
catalog in the COSMOS/UltraVISTA field. The differential number counts of sBzKs
and pBzKs are consistent with the results from the literature. Compared to the
observed results, semi-analytic models of galaxy formation and evolution
provide too few (many) galaxies at high (low)-mass end. Moreover, we find that
the star formation rate (SFR) and stellar mass of sBzKs follow the relation of
main sequence. Based on the HST/Wide Field Camera 3 (WFC3) F160W imaging, we
find a wide range of morphological diversities for sBzKs, from diffuse to
early-type spiral structures, with relatively high M20, large size and low G,
while pBzKs are elliptical-like compact morphologies with lower M20, smaller
size and higher G, indicating the more concentrated and symmetric spatial
extent of stellar population distribution in pBzKs than sBzKs. Furthermore, the
sizes of pBzKs (sBzKs) at z~2 are on average two to three (one to two) times
smaller than those of local early-type (late-type) galaxies with similar
stellar mass. Our findings imply that the two classes have different evolution
modes and mass assembly histories.
