2013ApJ...764L..31K

I use the abundance matching ansatz, which has proven to be successful in reproducing galaxy clustering and other statistics, to derive estimates of the virial radius, R₂₀₀, for galaxies of different morphological types and a wide range of stellar masses. I show that over eight orders of magnitude in stellar mass galaxies of all morphological types follow an approximately linear relation between half-mass radius of their stellar distribution, r _1/2, and virial radius, r_1/2~ 0.015 R₂₀₀, with scatter of ~0.2 dex. Such scaling is in remarkable agreement with the expectation of models that assume that galaxy sizes are controlled by halo angular momentum, r_1/2∝λR₂₀₀, where λ is the spin of galaxy parent halo. The scatter about the relation is comparable with the scatter expected from the distribution of λ. Moreover, I show that when the stellar and gas surface density profiles of galaxies of different morphological types are rescaled by the radius r_n= 0.015 R₂₀₀, the rescaled profiles follow approximately universal exponential (for late types) and de Vaucouleurs (for early types) form with scatter of only ~30%-50% at R ~ 1-3r_n . Remarkably, both late- and early-type galaxies have similar mean stellar surface density profiles at R ≳ 1r_n. The main difference between their stellar distributions is thus at R < r_n. The results of this study imply that galaxy sizes and radial distribution of baryons are shaped primarily by properties of their parent halos and that the sizes of both late-type disks and early-type spheroids are controlled by halo angular momentum.