SIMBAD references

Numerical models of gas inflow towards a supermassive black hole (SMBH) show that star formation may occur in such an environment through the growth of a gravitationally unstable gas disc. We consider the effect of nuclear activity on such a scenario. We present the first three-dimensional grid-based radiative hydrodynamic simulations of direct collisions between infalling gas streams and a 4 x 10⁶ M_☉ SMBH, using ray-tracing to incorporate radiation consistent with an active galactic nucleus (AGN). We assume inflow masses of ≃10⁵ M_☉ and explore radiation fields of 10 per cent and 100 per cent of the Eddington luminosity (L_edd). We follow our models to the point of central gas disc formation preceding star formation and use the Toomre Q parameter (Q_T) to test for gravitational instability. We find that radiation pressure from UV photons inhibits inflow. Yet, for weak radiation fields, a central disc forms on time-scales similar to that of models without feedback. Average densities of >10⁸ cm^–3 limit photoheating to the disc surface allowing for Q_T ≃ 1. For strong radiation fields, the disc forms more gradually resulting in lower surface densities and larger Q_T values. Mass accretion rates in our models are consistent with 1-60 per cent of the Eddington limit, thus we conclude that it is unlikely that radiative feedback from AGN activity would inhibit circumnuclear star formation arising from a massive inflow event.