Ratio between the median star formation rate (SFR) for AGN and non-AGN galaxies. The ratio is shown against the black hole (BH) mass over the stellar mass of the simulated galaxies. Those galaxies with over-massive black holes suffer a stronger suppression of the star formation.
Recent observational studies suggest that feedback from active galactic nuclei (AGNs)—the energetic centres powered by supermassive black holes—may play an important role in the formation and evolution of dwarf galaxies, contrary to the standard thought. We investigated this using two sets of 12 cosmological magnetohydrodynamic simulations of the formation of dwarf galaxies: one set using a version of the AURIGA galaxy formation physics model including AGN feedback and a parallel set with AGN feedback turned off. Our results reveal that AGNs can suppress the star formation (SF) of dwarf galaxies by heating and redistributing gas across the galaxy while leaving the total gas content intact, finding a tight correlation between the SF suppression and the ratio between the black hole mass and stellar mass in our galaxies. This process also alters the galaxy’s dark matter distribution by reducing its central dark matter density. This work highlights the importance of modelling AGN feedback at the lowest mass scales and the impact this can have on dwarf galaxy evolution.
