MOIRCS DEEP SURVEY. V. A UNIVERSAL RELATION FOR STELLAR MASS AND SURFACE BRIGHTNESS OF GALAXIES

We present a universal linear correlation between the stellar mass and surface brightness (SB) of galaxies at 0.3 < z < 3, using a deep K-band-selected catalog in the GOODS-North region. The correlation has a nearly constant slope, independent of redshift and color of galaxies in the rest-z frame. Considering unresolved compact galaxies, the tight correlation gives a lower boundary of SB for a given stellar mass; lower SB galaxies are prohibited over the boundary. The universal slope suggests that the stellar mass in galaxies was built up over their cosmic histories in a similar manner irrelevant to galaxy mass, as opposed to the scenario that massive galaxies mainly accumulated their stellar mass by major merging. In contrast, SB shows a strong dependence on redshift for a given stellar mass. It evolves as ∼(1 + z)-2.0∼-0.8, in addition to dimming as (1 + z)4 by the cosmological expansion effect. The brightening depends on galaxy color and stellar mass. The blue population (rest-frame U - V < 0), which is dominated by young and star-forming galaxies, evolves as ∼(1 + z)-0.8±0.3 in the rest-V band. On the other hand, the red population (U - V>0) and the massive galaxies (M*>1010 Msun) show stronger brightening, (1 + z)-1.5±0.1. By comparison with galaxy evolution models, the phenomena are well understood by the pure luminosity evolution of galaxies out to z ∼ 3.