Study of Asymptotic Velocity in the Bondi–Hoyle Accretion Flows in the Domain of Kerr and 4-D Einstein–Gauss–Bonnet Gravities

Understanding the physical structures of accreted matter very close to a black hole in quasars and active galactic nucleus (AGN) is an important milestone constrain activities occurring their centers. In this paper, we numerically investigate effects asymptotic velocities on accretion disk around Kerr Einstein–Gauss–Bonnet (EGB) rapidly rotating holes. The Bondi–Hoyle considered with falling gas towards upstream region computational domain. Shock cones are naturally formed downstream part flow both structure amount depend velocity V∞ (Mach number) types gravities (Kerr or EGB). Increasing Mach number in-flowing supersonic reduces shock opening angle rates, because hole. EGB gravity leads increase while mass-accretion rates dM/dt decrease Gauss–Bonnet (GB) coupling constant α. It also confirmed that drag forces significantly altered gravity. Our numerical simulation results could be used identifying mechanism properties observed X-rays such as NGC 1313 X-1 X-2 MAXI J1803-298.