Gas Inflow and Star Formation near Supermassive Black Holes: The Role of Nuclear Activity

Abstract

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 $4\times 10^6{\text{M}}_{\odot }$ SMBH, using ray-tracing to incorporate radiation consistent with an active galactic nucleus (AGN). We assume inflow masses of $\approx 10^5{\text{M}}_{\odot }$ and explore radiation fields of 10% and 100% of the Eddington luminosity ($L_{\text{edd}}$). 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 timescales similar to that of models without feedback. Average densities of $>10^8{\text{cm}}^{-3}$ limit photo-heating to the disc surface allowing for $Q_T\approx 1$. 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% 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.

29 pages, 27 figures, accepted by MNRAS

References in corpus (18)

• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• Athena: A New Code for Astrophysical MHD
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• An Update on Monitoring Stellar Orbits in the Galactic Center
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• The Birth of Molecular Clouds: Formation of Atomic Precursors in Colliding Flows
• Simulations of star formation in a gaseous disc around sgr A* - a failed AGN
• Star Formation Around Super-Massive Black Holes
• Self-gravitating accretion disk in Sgr A* few million years ago: was Sgr A* a failed quasar?
• Magnetohydronamic Evolution of HII Regions in Molecular Clouds: Simulation Methodology, Tests, and Uniform Media
• Simulations of the formation of stellar discs in the Galactic centre via cloud-cloud collisions
• The proper motion of the Arches cluster with Keck Laser-Guide Star Adaptive Optics
• On the Formation of Compact Stellar Disks Around Sgr A*
• Massive Star Formation in the Molecular Ring Orbiting the Black Hole at the Galactic Center
• On the evolution of gas clouds exposed to AGN radiation. I. Three-dimensional radiation hydrodynamic simulations
• The impact of X-rays on molecular cloud fragmentation and the IMF
• Black hole feedback in a multiphase interstellar medium
• Chemical enrichment of the pre-solar cloud by supernova dust grains

Cited by in corpus (1)

• Mass, Morphing, Metallicities: The Evolution of Infalling High Velocity Clouds