We revisit Bondi flows on black holes , naked singularities and neutron stars keeping in mind recent progress in understanding of the flow behaviour near compact objects .
In an adiabatic spherical accretion on black holes and naked singularities , standing shock waves do not form , but shocks on neutron stars may or may not form depending on the boundary conditions .
For low accretion rates ( hard state ) , these objects may behave similarly .
However , for high accretion rates ( soft state ) , the converging flow on a black hole will produce a weak hard tail of energy spectral slope of \sim 1.5 ( apart from the soft bump ) while the flow on a neutron star or a naked singularity will have no hard tail .
The soft bumps of neutron star candidates may generally be at higher energies than those of naked singularities .