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Strong evidence is emerging that winds can be driven from the central regionsof accretion disks in both active galactic nuclei (AGN) and Galactic black holebinaries (GBHBs). Direct evidence for highly-ionized, Compton-thin inner-diskwinds comes from observations of blueshifted (v~0.05-0.1c) iron-K X-rayabsorption lines. However, it has been suggested that the inner regions ofblack hole accretion disks can also drive Compton-thick winds --- such windswould enshroud the inner disk, preventing us from seeing direct signatures ofthe accretion disk (i.e. the photospheric thermal emission, or theDoppler/gravitationally broadened iron K-alpha line). Here, we show that,provided the source is sub-Eddington, the well-established wind drivingmechanisms fail to launch a Compton-thick wind from the inner disk. For theaccelerated region of the wind to be Compton-thick, the momentum carried in thewind must exceed the available photon momentum by a factor of at least2/lambda, where lambda is the Eddington ratio of the source, ruling outradiative acceleration unless the source is very close to the Eddington limit.Compton-thick winds also carry large mass-fluxes, and a consideration of theconnections between the wind and the disk show this to be incompatible withmagneto-centrifugal driving. Finally, thermal driving of the wind is ruled outon the basis of the large Compton-radii that typify black hole systems. In theabsence of some new acceleration mechanism, we conclude that the inner regionsof sub-Eddington accretion disks around black holes are indeed naked.

Constraints on Compton-thick winds from black hole accretion disks: can we see the inner disk?