The Evolution of the Mass-Size Relation to z = 3.5 for UV-bright Galaxies and Submillimeter Galaxies in the GOODS-North Field

Abstract

We study the evolution of the size-stellar mass relation for a large spectroscopic sample of galaxies in the GOODS-North field up to z ~ 3.5. The sizes of the galaxies are measured from K_s -band images (corresponding to rest-frame optical/NIR) from the Subaru 8 m telescope. We reproduce earlier results based on photometric redshifts that the sizes of galaxies at a given mass evolve with redshift. Specifically, we compare sizes of UV-bright galaxies at a range of redshifts: Lyman-break galaxies (LBGs) selected through the U-drop technique (z ~ 2.5-3.5), BM/BX galaxies at z ~ 1.5-2.5, and GALEX LBGs at low redshift (z ~ 0.6-1.5). The median sizes of these UV-bright galaxies evolve as (1 + z)^-1.11±0.13 between z ~ 0.5and3.5. The UV-bright galaxies are significantly larger than quiescent galaxies at the same mass and redshift by 0.45 ± 0.09 dex. We also verify the correlation between color and stellar mass density of galaxies to high redshifts. The sizes of submillimeter galaxies in the same field are measured and compared with BM/BX galaxies. We find that the median half-light radius of SMGs is 2.90 ± 0.45 kpc, and there is little difference in their size distribution to the UV-bright star-forming galaxies.