MORPHOLOGIES OF ∼ 190,000 GALAXIES AT z=0-10 REVEALED WITH HST LEGACY DATA. II. EVOLUTION OF CLUMPY GALAXIES

We investigate the. evolution of clumpy galaxies with. Hubble Space Telescope (HST) samples of similar to 17,000 photo-z and Lyman break galaxies at z similar or equal to 0-8. We detect clumpy galaxies with off-center clumps in a self-consistent algorithm that is well tested with previous study results, and we. measure the number fraction of clumpy galaxies at the rest-frame UV, f(clumpy)(UV). We identify an evolutionary trend of f(clumpy)(UV) over z similar or equal to 0-8 for the first time: f(clumpy)(UV) increases from z similar or equal to 8 to z similar or equal to 1-3 and subsequently decreases from z similar or equal to 1 to z similar or equal to 0, which follows the trend of the. Madau-Lilly plot. A low average Sersic index of n similar or equal to 1 is found in the underlining components of our clumpy galaxies at z similar or equal to 0-2, indicating that typical clumpy galaxies have disk-like surface brightness profiles. Our f(clumpy)(UV) values correlate with physical quantities related to star formation activities for star-forming galaxies at z similar or equal to 0-7. We find that clump colors tend to be red at a small galactocentric distance for massive galaxies with logM(*)/M-circle dot greater than or similar to 11. All of these results are consistent with the picture that a majority of clumps form in the violent disk instability and migrate into the galactic centers.