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arXiv · 2303.01536

Ionized gas kinematics and chemical abundances of low-mass star-forming galaxies at $z\sim 3$

M. Llerena·R. Amorín·L. Pentericci·A. Calabrò·A. E. Shapley·K. Boutsia·E. Pérez-Montero·J. M. Vílchez·K. Nakajima
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Abstract

We selected 35 low-mass SFGs (7.9 1000\r{A} and EW(CIII])>5\r{A}, closely resembling those now seen in EoR galaxies with JWST. We find low gas-phase metallicities 12+log(O/H)~7.5-8.5 and C/O abundances from 23%-128% solar, with no apparent increasing trend with metallicity. From our [OIII]4959,5007 profile modeling, we find that 65% of our sample shows an outflow component, which is shifted relative to the ionized gas systemic velocity, with mean $v_{max}$~280 km/s which correlates with the $\Sigma_{SFR}$. We find that the mass-loading factor $\mu$ of our sample is typically lower than in more massive galaxies from literature but higher than in typical local dwarf galaxies. In the stellar mass range covered, we find that $\mu$ increases with $\Sigma_{SFR}$ thus suggesting that for a given stellar mass, denser starbursts in low-mass galaxies produce stronger outflows. Our results complement the picture drawn by similar studies at lower redshift, suggesting that the removal of ionized gas in low-mass SFGs driven by stellar feedback is regulated by their stellar mass and by the strength and concentration of their star formation, i.e. $\Sigma_{\rm SFR}$.

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M. Llerena, R. Amorín, L. Pentericci, A. Calabrò, A. E. Shapley, K. Boutsia, E. Pérez-Montero, J. M. Vílchez, K. Nakajima. 2023-03-02. Ionized gas kinematics and chemical abundances of low-mass star-forming galaxies at $z\sim 3$. https://doi.org/10.1051/0004-6361/202346232

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