Bondi-like Accretion Flow Dynamics: The Role of Gravitational Potential

The formation of massive black holes and their coevolution with host galaxies are pivotal areas of modern astrophysics. Spherical accretion onto a central point mass serves as a foundational framework in cosmological simulations, semi-analytical models, and observational studies. In this paper, we extend the classical spherical accretion model by incorporating the gravitational potential of host galaxies, including contributions from stellar components and dark matter (DM) halos. Numerical solutions spanning scales from parsecs down to ∼10 r s reveal that the flow structure is highly sensitive to the mass and size of the DM halo. Adding a small amount of angular momentum to the accreting gas demonstrates that such flows resemble spherical Bondi accretion, with mass accretion rates converging toward the Bondi rate. We find that the low angular momentum flow resembles the spherical Bondi flow, and its mass accretion rate approaches the Bondi accretion rate. Remarkably, due to the presence of DM, the mass accretion rate increases by more than ∼100% compared to analogous hydrodynamic solutions without DM. These findings underscore the critical role of stellar and DM gravitational potentials in shaping the dynamics and accretion rates of quasi-spherical flows, providing new insights into astrophysical accretion processes.