Estimating the Fuel Supply Rate on the Galactic Disk from High-velocity Cloud (HVC) Infall

Abstract

Previous studies suggest that the estimated maximum accretion rate from approaching high-velocity clouds (HVCs) on the Galactic disk can be up to similar to 0.4 M-circle dot yr(-1). In this study, we point out that the hydrodynamic interaction between the HVCs and the Galactic disk is not considered in the traditional method of estimating the infall rate, and therefore the true supply rate of fuel from HVCs can be different from the suggested value depending on the physical configurations of HVCs including density, velocity, and distance. We choose 11 HVC complexes and construct four different infall models in our simulations to give an idea of how the fuel supply rate could be different from the traditional infall rate. Our simulation results show that the fuel supply rate from HVC infall is overestimated in the traditional method and can be lowered by a factor of similar to 0.072 when the hydrodynamic interaction of the HVC complexes and the disk is considered.