  The unmatched X-ray resolution of Chandra allows probing the gas flow near
quiescent supermassive black holes (BHs). The radius of BH gravitational
influence on gas, called the Bondi radius, is resolved in Sgr A* and NGC 3115.
Shallow accretion flow density profiles n \sim r^{-beta} with beta=0.7-1.0 were
found for Sgr A* and NGC 3115 with the help of Chandra. We construct
self-consistent models with gas feeding and dynamics from near the Bondi radius
to the event horizon to explain the observations. Gas is mainly supplied to the
region by hot colliding stellar winds. Small-scale feedback such as conduction
effectively flattens the density profile from steep beta=1.5 in a Bondi flow.
We further constrain density and temperature profiles using the observed
radio/sub-mm radiation emitted near the event horizon. We discuss the present
state of our numerical model and its qualitative features, such as the role of
the galactic gravitational potential and the random motion of wind-emitting
stars.
