UV-bright Star-forming Clumps and Their Host Galaxies in UVCANDELS at 0.5 ≤ z ≤ 1
Grogin, Norman A.; Hathi, Nimish P.; Koekemoer, Anton M.; Lucas, Ray A.; Ravindranath, Swara; Yung, L. Y. Aaron; Gardner, Jonathan P.; Teplitz, Harry I.; Conselice, Christopher J.; Rutkowski, Michael J.; Mehta, Vihang; Ji, Zhiyuan; Rafelski, Marc; Mobasher, Bahram; Chartab, Nima; Robertson, Brant E.; Windhorst, Rogier A.; Wang, Xin; Gawiser, Eric; Sattari, Zahra; Dekel, Avishai; Koo, David C.; Primack, Joel; Guo, Yicheng; Nedkova, Kalina V.; Jansen, Rolf A.; Mandelker, Nir; Soto, Emmaris; Alavi, Anahita; Sunnquist, Ben; Prichard, Laura; Hayes, Matthew J.; Dai, Y. Sophia; Martin, Alec; Ceverino, Daniel
United States, China, Spain, United Kingdom, Israel, Sweden
Abstract
Giant star-forming clumps are a prominent feature of star-forming galaxies (SFGs) and contain important clues on galaxy formation and evolution. However, the basic demographics of clumps and their host galaxies remain uncertain. Using the Hubble Space Telescope/Wide Field Camera 3 F275W images from the Ultraviolet Imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, we detect and analyze giant star-forming clumps in galaxies at 0.5 ≤ z ≤ 1, connecting two epochs when clumps are common (at cosmic high noon, z ~ 2) and rare (in the local Universe). We construct a clump sample whose rest-frame 1600 Å luminosity is 3 times higher than the most luminous local H II regions (M UV ≤ -16 AB). In our sample, 35% ± 3% of low-mass galaxies (log[M ∗/M ⊙] < 10) are clumpy (i.e., containing at least one off-center clump). This fraction changes to 22% ± 3% and 22% ± 4% for intermediate (10 ≤ log[M ∗/M ⊙] ≤ 10.5) and high-mass (log[M ∗/M ⊙] > 10.5) galaxies, in agreement with previous studies. When compared to similar-mass nonclumpy SFGs, low- and intermediate-mass clumpy SFGs tend to have higher star formation rates (SFRs) and bluer rest-frame U - V colors, while high-mass clumpy SFGs tend to be larger than nonclumpy SFGs. However, clumpy and nonclumpy SFGs have similar Sérsic index, indicating a similar underlying density profile. Furthermore, we investigate how the UV luminosity of star-forming regions correlates with the physical properties of host galaxies. On average, more luminous star-forming regions reside in more luminous, smaller, and/or higher specific SFR galaxies and are found closer to their hosts' galactic centers.