Inward And Outward Starburst Feedbacks And Growth Of Supermassive Black Holes

Based on the major merger scenario we propose a simple model to investigate the relation between the starburst and the central active galactic nuclei (AGN). We argue that the momentum feedback from the starburst rather than from the central black hole (BH) plays the most important role in the main growth stage of both the BH and the bulge. We suggest that for small scale, the momentum feedback from the starburst may exist in two directions. The outward starburst feedback can blow some gas away to halt the star formation activity, and the growth of the BH is regulated by the inward starburst feedback. The final BH mass is directly related to the maximum star formation rate based on this scenario, and such a relation can be used to derive the MBH-sigma and M-BH-M-bulge relations, which are consistent with recent observations and simulations. Our result suggests that the BH undergoes its main growth in an obscured environment, which may be just the "pre-quasar" phase, as some authors previously argued.