Demonstrating a New Census of Infrared Galaxies with ALMA (DANCING-ALMA). I. FIR Size and Luminosity Relation at z=0-6 Revealed with 1034 ALMA Sources

We present the large statistics of the galaxy effective radius R-e in the rest-frame far-infrared (FIR) wavelength Re(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 similar to 100-1000 M-circle dot yr(-1) and the stellar mass similar to 10(10)-10(11.5) M-circle dot 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) proportional to L-FIR(alpha), provides alpha = 0.28 +/- 0.07, and shows that R-e(FIR) at a fixed L-FIR decreases toward high redshifts. The best-fit alpha 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). less than or similar to 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 similar to 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 similar to 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).