談話会案内

日時

2012年05月21日(月) 15:00pm

場所

大輪講室

講演者

市川 隆 (東北大学　天文学専攻)

題目

A universal stellar-mass and size relation of galaxies

要旨

We found a universal scaling relation between stellar-mass and the size of galaxies at 0.3<z<3 for half- and 90 percent-light radii, using a deep K-band selected catalog taken with the Subaru Telescope and MOIRCS in the GOODS-North region. The logarithmic slope is independent of redshift in a wide mass range, irrespective of galaxy populations (star-forming, quiescent). The offset change is 50 percent or less. The universal relation demonstrates that the stellar mass was built up in galaxies over their cosmic histories in a similar manner on average irrelevant to galaxy mass. The small offset in each stellar mass bin from the universal relation shows weak size evolution at a given mass. The evolution of compactness factor, which becomes smaller at lower redshift, is suggestive of minor merging effect in the outer envelope of massive galaxies.