E. Shima et al., NUMERICAL COMPUTATION OF 2-DIMENSIONAL WIND ACCRETION OF ISOTHERMAL GAS, Astronomy and astrophysics (Berlin), 337(1), 1998, pp. 311-320
A new numerical algorithm for calculating isothermal wind accretion fl
ows has been developed and is applied here to the analysis of the hydr
odynamics of two-dimensional plane symmetric accretion flows in wind-f
ed sources. Polar coordinates are used to ensure fine resolution near
the object. It is found that a thin accretion column is formed which s
hows wave-like oscillations. Small accretion disks are formed temporar
ily ground the object. Mass accretion rate and angular momentum accret
ion rate exhibit quasi-periodic oscillations. The amplitudes of the os
cillations depend on the size of the inner boundary, the number of gri
d points and the method of calculation. For a smaller size of the inne
r boundary, finer grids and more accurate numerical schemes, the ampli
tudes of the oscillation become larger.