Energy feedback , either from active galactic nuclei ( AGN ) or from supernovae , is required to understand galaxy formation within a \Lambda -Cold Dark Matter cosmology .
We study a sample of 127 low-mass galaxies , comparing their stellar populations properties to the mass of the central supermassive black hole , in order to investigate the effect of AGN feedback .
We find a loose coupling between star formation history and black hole mass , which seems to suggest that AGN activity does not dominate baryonic cooling in low-mass galaxies .
We also find that a break in the M _ { \bullet } - \sigma relation marks a transitional stellar mass , M _ { \mathrm { trans } } = 3.4 \pm 2.1 \times 10 ^ { 10 } M _ { \odot } , remarkably similar to M _ { \star } .
Our results are in agreement with a bi-modal star formation process where the AGN-dominated feedback of high-mass galaxies transitions towards a supernovae-driven regime in low-mass systems , as suggested by numerical simulations .