Jet-driven active galactic nucleus feedback in galaxy formation before black hole formation

Abstract

We propose a scenario where during galaxy formation an active galactic nucleus (AGN) feedback mechanism starts before the formation of a supermassive black hole (SMBH). The supermassive star (SMS) progenitor of the SMBH accretes mass as it grows and launches jets. We simulate the evolution of SMSs and show that the escape velocity from their surface is ≈ several × 10 3 km s −1 , with large uncertainties. We could not converge with the parameters of the evolutionary numerical code mesa to resolve the uncertainties for SMS evolution. Under the assumption that the jets carry about ten percent of the mass of the SMS, we show that the energy in the jets is a substantial fraction of the binding energy of the gas in the galaxy/bulge. Therefore, the jets that the SMS progenitor of the SMBH launches carry sufficient energy to establish a feedback cycle with the gas in the inner zone of the galaxy/bulge, and hence, set a relation between the total stellar mass and the mass of the SMS. As the SMS collapses to form the SMBH at the center, there is already a relation (correlation) between the newly born SMBH mass and the stellar mass of the galaxy/bulge. During the formation of the SMBH it rapidly accretes mass from the collapsing SMS and launches very energetic jets that might unbind most of the gas in the galaxy/bulge.