Driving mechanism of the outflows in eFEDSJ091157.4+014327

Ascertain the physical driving mechanism(s) powering the kiloparsec-scale ionized outflows in the red quasar eFEDSJ091157.4+014327 (z ≈ 0.6), which cannot be firmly determined from the present ionized-gas analysis alone; determine whether these outflows are consistent with energy-conserving winds, radiation-pressure–driven flows, or other processes by incorporating multi-wavelength and multi-phase observations (e.g., radio and deeper X-ray data).

Background

Using spatially resolved MUSE data, the paper measures ionized outflow velocities up to ~1200 km s−1 and derives mass outflow rates and energetics. The inferred kinetic coupling efficiencies (~0.01–0.03%) and momentum boosts (~0.2) are lower than expectations from both radiation-pressure–driven and energy-conserving models, but the analysis is limited to the ionized phase.

Because the results rely only on the ionized gas, while theoretical predictions concern multi-phase outflows, and given the substantial uncertainties (e.g., electron density, geometry, velocity definitions), the authors conclude that the current data are insufficient to identify the outflow driving mechanism and call for additional observations at other wavelengths (e.g., radio and deeper X-ray) to probe other gas phases.