DESI DR1 yields 1502 AGN dwarf galaxies with outflows, establishing new velocity thresholds for AGN-driven feedback
The DESI DR1 study supplies the first large-scale empirical test of AGN feedback efficiency in the dwarf regime, showing that black-hole driven winds can escape low-mass halos more readily than in massive systems. This supplies a critical calibration point for cosmological simulations that have long over-predicted stellar masses in dwarfs. Future IFU and X-ray follow-up will be required to confirm multi-phase outflow properties and duty cycles.
The analysis draws on 7 million galaxies at z<0.45, isolating broad [OIII] components to flag ionized outflows then applying BPT diagnostics to separate AGN from star-forming systems. This yields 1502 AGN dwarfs with outflow signatures, a sample size that exceeds all prior targeted searches combined and directly quantifies how AGN feedback operates where supernova regulation was previously assumed dominant. In massive galaxies the AGN threshold rises to W80>350 km/s, revealing a mass-dependent transition that simulations must now reproduce. Outflow escape fractions are higher in dwarfs, enabling gas redistribution that can suppress star formation across the halo while enriching the circumgalactic medium.
Rodríguez Morales et al.: Within 18 months, TNG50-style simulations tuned with a 250 km/s AGN threshold in dwarfs will reduce the stellar-mass overprediction at 10^9 solar masses by at least 25%.
Sources (3)
- [1]Primary Source(https://arxiv.org/abs/2607.02655)
- [2]Supporting Source(https://ui.adsabs.harvard.edu/abs/2023MNRAS.523.2081M)
- [3]Supporting Source(https://ui.adsabs.harvard.edu/abs/2024ApJ...961..L15)