2017ApJ...850...83F

We present the large statistics of the galaxy effective radius R_e in the rest-frame far-infrared (FIR) wavelength R_e(FIR) obtained from 1627 Atacama Large Millimeter/submillimeter Array (ALMA) 1 mm band maps that become public by 2017 July. Our ALMA sample consists of 1034 sources with the star formation rate ∼100–1000 M_☉ yr^–1 and the stellar mass ∼10¹⁰–10^11.5 M_☉ at z = 0-6. We homogeneously derive R_e(FIR) and FIR luminosity L_FIR of our ALMA sources via the uv-visibility method with the exponential disk model, carefully evaluating selection and measurement incompletenesses by realistic Monte-Carlo simulations. We find that there is a positive correlation between R_e(FIR) and L_FIR at the >99% significance level. The best-fit power-law function, R_e(FIR)∝ L_FIR^α^, provides α=0.28±0.07, and shows that R_e(FIR) at a fixed L_FIR decreases toward high redshifts. The best-fit α and the redshift evolution of R_e(FIR) are similar to those of R_e in the rest-frame UV (optical) wavelength R_e(UV) (R_e(Opt.)) revealed by Hubble Space Telescope (HST) studies. We identify that our ALMA sources have significant trends of R_e(FIR) R_e(UV) and R_e(Opt.), which suggests that the dusty starbursts take place in compact regions. Moreover, R_e(FIR) of our ALMA sources is comparable to R_e(Opt.) of quiescent galaxies at z ∼ 1-3 as a function of stellar mass, supporting the evolutionary connection between these two galaxy populations. We also investigate rest-frame UV and optical morphologies of our ALMA sources with deep HST images, and find that ∼30%-40% of our ALMA sources are classified as major mergers. This indicates that dusty starbursts are triggered by not only the major mergers but also the other mechanism(s).