UV-bright Star-forming Clumps and Their Host Galaxies in UVCANDELS at 0.5 ≤ z ≤ 1

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 starforming clumps in galaxies at 0.5 <= z <= 1, connecting two epochs when clumps are common (at cosmic high noon, z similar to 2) and rare (in the local Universe). We construct a clump sample whose rest-frame 1600 angstrom luminosity is 3 times higher than the most luminous local H II regions (MUV <= -16 AB). In our sample, 35% +/- 3% of low-mass galaxies (log[M-*/M-circle dot] < 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-circle dot] <= 10.5) and high-mass (log[M*/M-circle dot] > 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 Sersic 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.

Automated summary

Giant star-forming clumps are important features of star-forming galaxies, providing insights into galaxy formation and evolution. This study examines the characteristics of clumps in galaxies of different masses and their correlations with the physical properties of their host galaxies.