The MOSDEF survey: The dependence of H α-to-UV SFR ratios on SFR and size at z ∼2
Author
Fetherolf, T.Reddy, N.A.
Shapley, A.E.
Kriek, M.
Siana, B.
Coil, A.L.
Mobasher, B.
Freeman, W.R.
Sanders, R.L.
Price, S.H.
Shivaei, I.
Azadi, M.
de Groot, L.
Leung, G.C.K.
Zick, T.O.
Affiliation
Steward Observatory, University of ArizonaIssue Date
2021Keywords
Galaxies: EvolutionGalaxies: Fundamental parameters
Galaxies: High-redshift
Galaxies: Star formation
Methods: Data analysis
Metadata
Show full item recordPublisher
Oxford University PressCitation
Fetherolf, T., Reddy, N. A., Shapley, A. E., Kriek, M., Siana, B., Coil, A. L., Mobasher, B., Freeman, W. R., Sanders, R. L., Price, S. H., Shivaei, I., Azadi, M., de Groot, L., Leung, G. C. K., & Zick, T. O. (2021). The MOSDEF survey: The dependence of H α-to-UV SFR ratios on SFR and size at z ∼2. Monthly Notices of the Royal Astronomical Society.Rights
Copyright © 2021 The Author(s).Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
We perform an aperture-matched analysis of dust-corrected H α and UV star formation rates (SFRs) using 303 star-forming galaxies with spectroscopic redshifts 1.36 < zspec < 2.66 from the MOSFIRE Deep Evolution Field survey. By combining H α and H β emission line measurements with multiwaveband resolved Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey/3D-HST imaging, we directly compare dust-corrected H α and UV SFRs, inferred assuming a fixed attenuation curve shape and constant SFHs, within the spectroscopic aperture. Previous studies have found that H α and UV SFRs inferred with these assumptions generally agree for typical star-forming galaxies, but become increasingly discrepant for galaxies with higher SFRs (Z100 M⊙ yr-1), with H α-to-UV SFR ratios being larger for these galaxies. Our analysis shows that this trend persists even after carefully accounting for the apertures over which H α and UV-based SFRs (and the nebular and stellar continuum reddening) are derived. Furthermore, our results imply that H α SFRs may be higher in the centres of large galaxies (i.e. where there is coverage by the spectroscopic aperture) compared to their outskirts, which could be indicative of inside-out galaxy growth. Overall, we suggest that the persistent difference between nebular and stellar continuum reddening and high H α-to-UV SFR ratios at the centres of large galaxies may be indicative of a patchier distribution of dust in galaxies with high SFRs. © 2021 The Author(s).Note
Immediate accessISSN
0035-8711Version
Final published versionae974a485f413a2113503eed53cd6c53
10.1093/mnras/stab2570