TY - JOUR
T1 - Fraction of Clumpy Star-forming Galaxies at 0.5 ≤ z ≤ 3 in UVCANDELS
T2 - Dependence on Stellar Mass and Environment
AU - Sattari, Zahra
AU - Mobasher, Bahram
AU - Chartab, Nima
AU - Kelson, Daniel D.
AU - Teplitz, Harry I.
AU - Rafelski, Marc
AU - Grogin, Norman A.
AU - Koekemoer, Anton M.
AU - Wang, Xin
AU - Windhorst, Rogier A.
AU - Alavi, Anahita
AU - Prichard, Laura
AU - Sunnquist, Ben
AU - Gardner, Jonathan P.
AU - Gawiser, Eric
AU - Hathi, Nimish P.
AU - Hayes, Matthew J.
AU - Ji, Zhiyuan
AU - Mehta, Vihang
AU - Robertson, Brant E.
AU - Scarlata, Claudia
AU - Yung, L. Y.Aaron
AU - Conselice, Christopher J.
AU - Dai, Y. Sophia
AU - Guo, Yicheng
AU - Lucas, Ray A.
AU - Martin, Alec
AU - Ravindranath, Swara
N1 - Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/7/1
Y1 - 2023/7/1
N2 - High-resolution imaging of galaxies in rest-frame UV has revealed the existence of giant star-forming clumps prevalent in high-redshift galaxies. Studying these substructures provides important information about their formation and evolution and informs theoretical galaxy evolution models. We present a new method to identify clumps in galaxies’ high-resolution rest-frame UV images. Using imaging data from CANDELS and UVCANDELS, we identify star-forming clumps in an HST/F160W ≤ 25 AB mag sample of 6767 galaxies at 0.5 ≤ z ≤ 3 in four fields, GOODS-N, GOODS-S, EGS, and COSMOS. We use a low-passband filter in Fourier space to reconstruct the background image of a galaxy and detect small-scale features (clumps) on the background-subtracted image. Clumpy galaxies are defined as those having at least one off-center clump that contributes a minimum of 10% of the galaxy’s total rest-frame UV flux. We measure the fraction of clumpy galaxies (f clumpy) as a function of stellar mass, redshift, and galaxy environment. Our results indicate that f clumpy increases with redshift, reaching ∼65% at z ∼ 1.5. We also find that f clumpy in low-mass galaxies ( 9.5 ≤ log ( M * / M ⊙ ) ≤ 10 ) is 10% higher compared to that of their high-mass counterparts ( log ( M * / M ⊙ ) > 10.5 ). Moreover, we find no evidence of significant environmental dependence of f clumpy for galaxies at the redshift range of this study. Our results suggest that the fragmentation of gas clouds under violent disk instability remains the primary driving mechanism for clump formation, and incidents common in dense environments, such as mergers, are not the dominant processes.
AB - High-resolution imaging of galaxies in rest-frame UV has revealed the existence of giant star-forming clumps prevalent in high-redshift galaxies. Studying these substructures provides important information about their formation and evolution and informs theoretical galaxy evolution models. We present a new method to identify clumps in galaxies’ high-resolution rest-frame UV images. Using imaging data from CANDELS and UVCANDELS, we identify star-forming clumps in an HST/F160W ≤ 25 AB mag sample of 6767 galaxies at 0.5 ≤ z ≤ 3 in four fields, GOODS-N, GOODS-S, EGS, and COSMOS. We use a low-passband filter in Fourier space to reconstruct the background image of a galaxy and detect small-scale features (clumps) on the background-subtracted image. Clumpy galaxies are defined as those having at least one off-center clump that contributes a minimum of 10% of the galaxy’s total rest-frame UV flux. We measure the fraction of clumpy galaxies (f clumpy) as a function of stellar mass, redshift, and galaxy environment. Our results indicate that f clumpy increases with redshift, reaching ∼65% at z ∼ 1.5. We also find that f clumpy in low-mass galaxies ( 9.5 ≤ log ( M * / M ⊙ ) ≤ 10 ) is 10% higher compared to that of their high-mass counterparts ( log ( M * / M ⊙ ) > 10.5 ). Moreover, we find no evidence of significant environmental dependence of f clumpy for galaxies at the redshift range of this study. Our results suggest that the fragmentation of gas clouds under violent disk instability remains the primary driving mechanism for clump formation, and incidents common in dense environments, such as mergers, are not the dominant processes.
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U2 - 10.3847/1538-4357/acd5d6
DO - 10.3847/1538-4357/acd5d6
M3 - Article
AN - SCOPUS:85165338448
SN - 0004-637X
VL - 951
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 147
ER -