Abstract A majority of JWST/NIRSpec/IFU studies at high redshifts to date have focused on UV-bright or massive objects, while our understanding of low-mass galaxies at early cosmic times remains limited. In this work, we present NIRSpec/IFS high-resolution observations of two low-mass (M* 109 M⊙), low-metallicity (12 + log (O/H) 8) galaxies at z ∼ 7.66, one of which we identify as hosting a Type-II AGN. We measure flat strong-line metallicity gradients, suggestive of ISM redistribution by outflows or past merging, but also identify tension with the direct-Te metallicity gradient in one galaxy. We find the ionised gas phase in both galaxies to be dispersion-dominated, consistent with previous observations of lower rotational support at early cosmic times. We identify broad kinematical components decoupled from galactic rotation with velocities of ∼250 − 500 km s−1and argue these components trace outflows, for which we infer mass outflow rates of ∼8 − 14 M⊙ yr−1. We compare our findings to results from the new large-volume Aesopica simulations, which fully incorporate different models of black hole growth and AGN feedback. We find that our observationally-measured ratios of outflow to escape velocity are consistent with those of the simulated dwarf AGN population, hinting that AGN-driven feedback may contribute to quenching in early low-mass galaxies such as our targets. This novel study illustrates the necessity of deep IFU observations to decompose the complex kinematics and morphology of high-z galaxies, trace outflows, and constrain the effects of feedback in the early Universe.
Ivey et al. (Wed,) studied this question.