Journal article
Discovery of Strongly Inverted Metallicity Gradients in Dwarf Galaxies at z ∼ 2
X Wang, TA Jones, T Treu, J Hirtenstein, GB Brammer, E Daddi, XL Meng, T Morishita, LE Abramson, AL Henry, YJ Peng, KB Schmidt, K Sharon, M Trenti, B Vulcani
Astrophysical Journal | IOP PUBLISHING LTD | Published : 2019
Abstract
We report the first measurements with sub-kiloparsec spatial resolution of strongly inverted gas-phase metallicity gradients in two dwarf galaxies at z ∼ 2. The galaxies have stellar masses ∼109 , specific star formation rate ∼20 Gyr-1, and global metallicity (1/4 solar), assuming the strong-line calibrations of [O iii]/Hβ and [O ii]/Hβ from Maiolino et al. Their radial metallicity gradients are measured to be highly inverted, i.e., 0.122 ± 0.008 and 0.111 ± 0.017 dex kpc-1, which is hitherto unseen at such small masses in similar redshift ranges. From the Hubble Space Telescope observations of the source nebular emission and stellar continuum, we present two-dimensional spatial maps of star..
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Awarded by NASA through HST grant
Awarded by National Key Program for Science and Technology Research and Development
Awarded by NSFC
Funding Acknowledgements
We thank the Astrophysical Journal and especially the editor Prof. Brad Gibson for a thoughtful and constructive review process that improved the quality of our manuscript. This study makes use of the Hubble Space Telescope data collected by the GLASS program. We gratefully acknowledge support by NASA through HST grant HST-GO-13459. X.W. is supported by the UCLA Graduate Division Dissertation Year Fellowship. X.W. thanks Michele Cappellari, Renyue Cen, Tuan Do, Phil Hopkins, Bethan James, Suoqing Ji, Dusan Keres, Claus Leitherer, Xiangcheng Ma, Roberto Maiolino, Yong Shi, Enci Wang, Pieter van Dokkum, Anita Zanella, and Dong Zhang for helpful discussions. Y.P. acknowledges support from the National Key Program for Science and Technology Research and Development under grant No. 2016YFA0400702, and the NSFC grant No. 11773001.