TY - JOUR
T1 - A Spatially Resolved Analysis of Star Formation Burstiness by Comparing UV and Hα in Galaxies at z ∼ 1 with UVCANDELS
AU - Mehta, Vihang
AU - Teplitz, Harry I.
AU - Scarlata, Claudia
AU - Wang, Xin
AU - Alavi, Anahita
AU - Colbert, James
AU - Rafelski, Marc
AU - Grogin, Norman
AU - Koekemoer, Anton
AU - Prichard, Laura
AU - Windhorst, Rogier
AU - Barber, Justin M.
AU - Conselice, Christopher J.
AU - Dai, Y. Sophia
AU - Gardner, Jonathan P.
AU - Gawiser, Eric
AU - Guo, Yicheng
AU - Hathi, Nimish
AU - Haro, Pablo Arrabal
AU - Hayes, Matthew
AU - Iyer, Kartheik G.
AU - Jansen, Rolf A.
AU - Ji, Zhiyuan
AU - Kurczynski, Peter
AU - Kuschel, Maxwell
AU - Lucas, Ray A.
AU - Mantha, Kameswara
AU - O’Connell, Robert W.
AU - Ravindranath, Swara
AU - Robertson, Brant E.
AU - Rutkowski, Michael
AU - Siana, Brian
AU - Yung, L. Y.Aaron
N1 - Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/8/1
Y1 - 2023/8/1
N2 - The UltraViolet imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey Fields (UVCANDELS) program provides Hubble Space Telescope (HST)/UVIS F275W imaging for four CANDELS fields. We combine this UV imaging with existing HST/near-IR grism spectroscopy from 3D-HST+AGHAST to directly compare the resolved rest-frame UV and Hα emission for a sample of 979 galaxies at 0.7 < z < 1.5, spanning a range in stellar mass of 108−11.5 M ⊙. Using a stacking analysis, we perform a resolved comparison between homogenized maps of rest-UV and Hα to compute the average UV-to-Hα luminosity ratio (an indicator of burstiness in star formation) as a function of galactocentric radius. We find that galaxies below stellar mass of ∼109.5 M ⊙, at all radii, have a UV-to-Hα ratio higher than the equilibrium value expected from constant star formation, indicating a significant contribution from bursty star formation. Even for galaxies with stellar mass ≳109.5 M ⊙, the UV-to-Hα ratio is elevated toward their outskirts (R/R eff > 1.5), suggesting that bursty star formation is likely prevalent in the outskirts of even the most massive galaxies, but is likely overshadowed by their brighter cores. Furthermore, we present the UV-to-Hα ratio as a function of galaxy surface brightness, a proxy for stellar mass surface density, and find that regions below ∼107.5 M ⊙ kpc−2 are consistent with bursty star formation, regardless of their galaxy stellar mass, potentially suggesting that local star formation is independent of global galaxy properties at the smallest scales. Last, we find galaxies at z > 1.1 to have bursty star formation, regardless of radius or surface brightness.
AB - The UltraViolet imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey Fields (UVCANDELS) program provides Hubble Space Telescope (HST)/UVIS F275W imaging for four CANDELS fields. We combine this UV imaging with existing HST/near-IR grism spectroscopy from 3D-HST+AGHAST to directly compare the resolved rest-frame UV and Hα emission for a sample of 979 galaxies at 0.7 < z < 1.5, spanning a range in stellar mass of 108−11.5 M ⊙. Using a stacking analysis, we perform a resolved comparison between homogenized maps of rest-UV and Hα to compute the average UV-to-Hα luminosity ratio (an indicator of burstiness in star formation) as a function of galactocentric radius. We find that galaxies below stellar mass of ∼109.5 M ⊙, at all radii, have a UV-to-Hα ratio higher than the equilibrium value expected from constant star formation, indicating a significant contribution from bursty star formation. Even for galaxies with stellar mass ≳109.5 M ⊙, the UV-to-Hα ratio is elevated toward their outskirts (R/R eff > 1.5), suggesting that bursty star formation is likely prevalent in the outskirts of even the most massive galaxies, but is likely overshadowed by their brighter cores. Furthermore, we present the UV-to-Hα ratio as a function of galaxy surface brightness, a proxy for stellar mass surface density, and find that regions below ∼107.5 M ⊙ kpc−2 are consistent with bursty star formation, regardless of their galaxy stellar mass, potentially suggesting that local star formation is independent of global galaxy properties at the smallest scales. Last, we find galaxies at z > 1.1 to have bursty star formation, regardless of radius or surface brightness.
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U2 - 10.3847/1538-4357/acd9cf
DO - 10.3847/1538-4357/acd9cf
M3 - Article
AN - SCOPUS:85166112829
SN - 0004-637X
VL - 952
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 133
ER -