2003MNRAS.345..657K

We show that black holes accreting at or above the Eddington rate probably produce winds that are optically thick in the continuum, whether in quasars or in X-ray binaries. The photospheric radius and outflow speed are proportional to {formmu1} and {formmu2} respectively, where {formmu3} is the mass outflow rate. The momentum outflow rate is always of the order of L_Edd/c. Blackbody emission from these winds may provide the big blue bump in some quasars and active galactic nuclei, as well as ultrasoft X-ray components in ultraluminous X-ray sources.