Star formation is one of the key mechanisms driving the evolution of galaxies across cosmic times. The environment certainly plays a role in star formation. In particular, recent studies suggest that AGN can regulate gas accretion and slow down star formation (negative feedback). However, evidence of AGN positive feedback is also invoked in a few radio galaxies.
One of those example is the nearby galaxy Centaurus A. This region is a testbed for positive feedback, here through jet-induced star formation. Filaments extend on scales up to 15 kpc and show evidence of recent star formation. By mapping the CO emission with APEX and ALMA, we concluded that the energy injected by the jet acts positively in the formation of molecular gas. On the other hand, the injected kinetic energy is too strong for star formation to be efficient. This is the first evidence of inefficient AGN positive feedback.
Comparing the CO emission with other wavelengths, we hypothesised that the filaments present two different regions: one inside the HI cloud (that seems not affected by the jet) and one along the jet direction, at the edge of the HI cloud (that seems to be facing the effect of the jet). Such difference in the star formation regime might be due to difference in the physical conditions of the molecular clouds. To test this, we conduct studies at different resolutions based on several CO mid-J lines, that I will present during the meeting.
Enviado por qsalome@inaoep.mx, 2019 Oct