Mass‐dependent Color Evolution of Field Galaxies back toz ∼ 3 over the Wide Range of Stellar Mass

We use deep multi-band optical and near-infrared data for four generalfields, GOODS-South, HDF North/South, and IRAC UDF in GOODS-North toinvestigate the evolution of the observed rest-frame U-V color of fieldgalaxies as a function of the stellar mass. In these four fields, the U-V colordistributions of the galaxies at each mass and redshift interval are verysimilar. At 0.3 3x10^10M_solar)evolves more strongly at a high redshift. Such mass-dependent colordistribution and its evolution indicate that galaxies with a larger stellarmass appear to have shorter star-formation timescales, and on an average, theyform the larger fraction of their stars in the earlier epoch.Comment: 7 pages, 3 color figures, accepted for publication in Ap