Mapping Jet-gas Coupling and Energetic Ionized Outflows in High-redshift Radio Galaxies with JWST/NIRSpec

Abstract

We present spatially resolved maps of morphology, kinematics, and energetics of warm ionized gas in six powerful radio galaxies at z ∼ 3.5-4, using JWST/NIRSpec integral field unit to quantify jet-driven feedback in the early Universe. All sources exhibit broad [O III] emission-line profiles with W80 (line width) values of 950–2500 km s−1 across approximately tens of kiloparsecs, signifying large-scale outflows. The outflowing nebulae are preferentially aligned with the radio jet axis, suggesting a jet-driven origin. On average, the regions with the broadest lines and highest velocities are co-spatial with radio lobes or cores, and exhibit the strongest kinetic power. Ionized gas masses associated with the outflows span from ∼1 to 8 × 109M⊙, with total mass outflow rates of 80–950 M⊙ yr−1 and kinetic powers between 1043.2 and 1045.0 erg s−1. The outflow kinetic power corresponds to 0.15%–2% of the AGN bolometric luminosity, sufficient to impact galaxy evolution. However, only ≲1% of the jet's mechanical energy couples to the warm ionized gas via outflows, consistent with predictions from hydrodynamic simulations. A large fraction of the jet energy may instead reside in shock-heated hot gas, supported by X-ray detection, or used to thermalize the gas and produce the observed emission-line nebulae. Our results demonstrate that radio jets in massive, gas-rich systems at high redshift can inject significant kinetic and thermal energy into the surroundings, providing direct evidence for jet-driven feedback operating during the peak epoch of galaxy formation.