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 108−11.5M⊙. 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 ∼109.5M⊙, 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 ≳109.5M⊙, the UV-to-Hα ratio is elevated toward their outskirts (R/Reff > 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 ∼107.5M⊙ 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.
A Spatially Resolved Analysis of Star Formation Burstiness by Comparing UV and Hα in Galaxies at z ∼ 1 with UVCANDELS
- Creators
- Mehta, Vihang
- Teplitz, Harry I.
- Scarlata, Claudia
- Wang, Xin
- Alavi, Anahita
- Colbert, James
- Rafelski, Marc
- Grogin, Norman
- Koekemoer, Anton
- Prichard, Laura
- Windhorst, Rogier
- Barber, Justin M.
- Conselice, Christopher J.
- Dai 戴, Y. Sophia 昱
- Gardner, Jonathan P.
- Gawiser, Eric
- Guo, Yicheng
- Hathi, Nimish
- Arrabal Haro, Pablo
- Hayes, Matthew
- Iyer, Kartheik G.
- Jansen, Rolf A.
- Ji, Zhiyuan
- Kurczynski, Peter
- Kuschel, Maxwell
- Lucas, Ray A.
- Mantha, Kameswara
- O'Connell, Robert W.
- Ravindranath, Swara
- Robertson, Brant E.
- Rutkowski, Michael
- Siana, Brian
- Yung, L. Y. Aaron
Abstract
Copyright and License
© 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Acknowledgement
We would like to acknowledge Dr. Gabriel Brammer for their critical contribution in the Grizli reduction of 3D-HST grism spectroscopy data as part of the Complete Hubble Archive for Galaxy Evolution (CHArGE) initiative. The analysis presented in this paper is based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. Support for Program Number HST-GO-15647 was provided through a grant from the STScI under NASA contract NAS5-26555. V.M., H.T., and X.W. acknowledge work carried out, in part, by IPAC at the California Institute of Technology, as was sponsored by the National Aeronautics and Space Administration.
Facilities
HST (WFC3) - Hubble Space Telescope satellite, HST (ACS) - Hubble Space Telescope satellite
Software References
NumPy, SciPy, AstroPy, Matplotlib, Grizli (Brammer & Matharu 2021), SWarp (Bertin et al. 2002), PyPHER (Boucaud et al. 2016), Dense Basis (Iyer et al. 2019)
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Additional details
- ISSN
- 1538-4357
- National Aeronautics and Space Administration
- NAS5-26555
- National Aeronautics and Space Administration
- HST-GO-15647
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)