Morphologies of ∼190,000 galaxies at z = 0–10 revealed with HST legacy data. II. Evolution of clumpy galaxies
- Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan)
We investigate the evolution of clumpy galaxies with Hubble Space Telescope (HST) samples of ∼17,000 photo-z and Lyman break galaxies at z ≃ 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{sub clumpy}{sup UV}. We identify an evolutionary trend of f{sub clumpy}{sup UV} over z ≃ 0–8 for the first time: f{sub clumpy}{sup UV} increases from z ≃ 8 to z ≃ 1–3 and subsequently decreases from z ≃ 1 to z ≃ 0, which follows the trend of the Madau–Lilly plot. A low average Sérsic index of n ≃ 1 is found in the underlining components of our clumpy galaxies at z ≃ 0–2, indicating that typical clumpy galaxies have disk-like surface brightness profiles. Our f{sub clumpy}{sup UV} values correlate with physical quantities related to star formation activities for star-forming galaxies at z ≃ 0–7. We find that clump colors tend to be red at a small galactocentric distance for massive galaxies with logM{sub ∗}/M{sub ⊙} ≳ 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.
- OSTI ID:
- 22890064
- Journal Information:
- Astrophysical Journal, Vol. 821, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Since 2009, the country of publication for this journal is the UK.; ISSN 0004-637X
- Country of Publication:
- United Kingdom
- Language:
- English
Similar Records
Morphologies of ∼190,000 galaxies at z = 0–10 revealed with HST legacy data. I. size evolution
No more active galactic nuclei in clumpy disks than in smooth galaxies at z ∼ 2 in CANDELS/3D-HST