2023ApJ...955L..18L -
Astrophys. J., 955, L18 (2023/September-3)
The Mass-Metallicity Relation of Dwarf Galaxies at Cosmic Noon from JWST Observations.
LI M., CAI Z., BIAN F., LIN X., LI Z., WU Y., SUN F., ZHANG S., GOLDEN-MARX E., SUN Z., ZOU S., FAN X., EGAMI E., CHARLOT S., BRUZUAL G. and CHEVALLARD J.
Abstract (from CDS):
We present a study of the mass-metallicity relation (MZR) of 51 dwarf galaxies (M⋆ ≈ 106.5-109.5M⊙) at z = 2-3 from the A2744 and SMACS J0723-3732 galaxy cluster fields. These dwarf galaxies are identified and confirmed by deep JWST/NIRISS imaging and slitless grism spectroscopic observations. By taking advantage of the superior performance of JWST and the gravitational lensing effect, we extend the previous MZR relation at z = 2-3 to a much lower-mass regime down by ≈2.5 orders of magnitude as compared with previous studies. We find that the MZR has a shallower slope at the low-mass end (M⋆ < 109M⊙), with a slope turnover point of ≈109M⊙. This implies that the dominating feedback processes in dwarf galaxies may be different from that in massive galaxies. From z = 3, to z = 2, the metallicity of the dwarf galaxies is enhanced by ≈0.09 dex for a given stellar mass, consistent with the mild evolution found in galaxies with higher mass. Furthermore, we confirm the existence of a fundamental metallicity relation (FMR) between the gas-phase metallicity, stellar mass, and star formation rate in dwarf galaxies at z = 2-3. Our derived FMR, which has no significant redshift evolution, can be used as a benchmark to understand the origin of the anticorrelation between the star formation rate and metallicity of dwarf galaxies in the high-z Universe.
Abstract Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
Journal keyword(s):
Galaxy abundances - Interstellar medium - Galaxy evolution - High-redshift galaxies
Nomenclature:
Tables A1-A2: [LCB2023] NNNN N=51 among (Nos 34-2421).
Simbad objects:
53
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