Work

New constraints on stellar feedback through [O iii ] emission: interpreting ALMA and JWST observations with spice simulations

Year: 2026

Type: article

Abstract: ABSTRACT Atacama Large Millimeter/submillimeter Array and James Webb Space Telescope detected emission lines from the interstellar medium of star-forming galaxies during the epoch of reionization, reaching redshifts up to $z=14$. Among these, $\rm{[O\,{\small III}]}$ lines offer a powerful diagnostic of metal enrichment, gas ionization, and the impact of stellar feedback in galaxies at $z\gt 6$. Modelling such emission in cosmological simulations is challenging due to the wide range of spatial scales and physical processes involved. To address this, we develop a post-processing pipeline that implements a subgrid model for $\rm{[O\,{\small III}]}$ line emission within the spice radiation-hydrodynamical simulations. The simulation explores three supernova feedback prescriptions – bursty-sn, smooth-sn, and the hypernova-based hyper-sn. We examine how these feedback modes affect metal enrichment, neutral gas fraction, size, and morphology of the ionized haloes traced by $\rm{[O\,{\small III}]}$ emission in the optical and far-infrared rest frame. We find that $\rm{[O\,{\small III}]}$ emission predominantly arises from gas that is both shock-heated and radiatively ionized. We further characterize the mass–metallicity relation and the correlation between neutral gas fraction and $\rm{[O\,{\small III}]}$ luminosity. Bursty-sn efficiently ionizes gas but enriches galaxies less effectively by $z = 5$. This leads to fewer bright $\rm{[O\,{\small III}]}$ emitters than in the smooth-sn model, with both bursty-sn and hyper-sn showing suppressed luminosity functions. Spatially resolved $\rm{[O\,{\small III}]}$ emission shows that smooth-sn generally produces more compact galaxies and slightly higher $V /\sigma$ values, though with overlap among models. Our results demonstrate that $\rm{[O\,{\small III}]}$ emission is a sensitive tracer of stellar feedback at high redshift and highlight the need for observations reaching fainter luminosities where feedback effects are strongest.

Source: Monthly Notices of the Royal Astronomical Society

DOI: 10.1093/mnras/stag872

Authors: Benedetta Casavecchia, Aniket Bhagwat, Benedetta Ciardi, Céline Péroux, Tiago Costa