Gaseous Dynamical Friction in Presence of Black Hole Radiative Feedback

Understand

Dynamical friction is thought to be a principal mechanism responsible for orbital evolution of massive black holes (MBHs) in the aftermath of galactic mergers and an important channel for formation of gravitationally bound MBH binaries.

• We use 2D radiative hydrodynamic simulations to investigate the efficiency of dynamical friction in the presence of radiative feedback from an MBH moving through a uniform density gas.
• We find that ionizing radiation that emerges from the innermost parts of the MBH's accretion flow strongly affects the dynamical friction wake and renders dynamical friction inefficient for a range of physical scenarios.
• MBHs in this regime tend to experience positive net acceleration, meaning that they speed up, contrary to the expectations for gaseous dynamical friction in absence of radiative feedback.