The Evolution of Advanced Merger (U)LIRGs on the Color-Stellar Mass
  Diagram
  Based on a sample of 79 local advanced merger (adv-merger) (U)LIRGs, we
search for the evidence of quenching process by investigating the distributions
of the star formation history indicators (EW(H$\alpha$), EW(H$\delta$$_A$) and
D$_n(4000)$) on the NUV-r color-mass and SFR-$M_{\ast}$ diagrams. The
distributions of the EW(H$\alpha$) and D$_n(4000)$ on the NUV-r color-mass
diagram show clear trends that at a given stellar mass, galaxies with redder
NUV-r colors have smaller EW(H$\alpha$) and larger D$_n(4000)$. The reddest
adv-merger (U)LIRGs close to the green valley have D$_n(4000)$$>1.4$ mostly. In
addition, in the SFR-$M_{\ast}$ diagram, as the SFR decreases, the
EW(H$\alpha$) decreases and the D$_n(4000)$ increases, implying that the
adv-merger (U)LIRGs on the star formation main sequence have more evolved
stellar populations than those above the main sequence. These results indicate
that a fraction of the adv-merger (U)LIRGs have already exhibited signs of
fading from the starburst phase and that the NUV-r reddest adv-merger (U)LIRGs
are likely at the initial stage of post-starbursts with age of $\sim 1$ Gyr,
which is consistent with the gas exhausting time-scales. Therefore, our results
offer additional support for the fast evolutionary track from the blue cloud to
the red sequence.
