Lee, Joon HyeopPak, MinaLee, Hye-RanOh, Sree2019-09-022019-09-020004-637Xhttp://hdl.handle.net/1885/165450We investigate the properties of bright galaxies of various morphological types in Abell 1139 and Abell 2589, using pixel color-magnitude diagram (pCMD) analysis. The sample contains 32 galaxies brighter than M-r = -21.3 mag with spectroscopic redshifts, which are deeply imaged in the g and r bands using the MegaCam mounted on the Canada-France-Hawaii Telescope. After masking contaminants with two-step procedures, we examine how the detailed properties in the pCMDs depend on galaxy morphology and infrared color. The mean g - r color as a function of surface brightness (mu(r)) in the pCMD of a galaxy shows good performance in distinguishing between early- and late-type galaxies, but it is not perfect because of the similarity between elliptical galaxies and bulge-dominated spiral galaxies. On the other hand, the g - r color dispersion as a function of mu(r) works better. We find that the best set of parameters for galaxy classification is a combination of the minimum color dispersion at mu(r) <= 21.2 mag arcsec(-2) and the maximum color dispersion at 20.0 <= mu(r) <= 21.0 mag arcsec(-2); the latter reflects the complexity of stellar populations at the disk component in a typical spiral galaxy. Finally, the color dispersion measurements of an elliptical galaxy appear to be correlated with the Wide-field Infrared Survey Explorer infrared color ([4.6]-[12]). This indicates that the complexity of stellar populations in an elliptical galaxy is related to its recent star formation activities. From this observational evidence, we infer that gas-rich minor mergers or gas interactions may have usually occurred during the recent growth of massive elliptical galaxies.application/pdfen-AU© 2018. The American Astronomical SocietyColor Dispersion as an Indicator of Stellar Population Complexity: Insights from the Pixel Color-Magnitude Diagrams of 32 Bright Galaxies in Abell 1139 and Abell 2589201810.3847/1538-4357/aab8922019-04-14