THE WARPED DISK OF CENTAURUS-A IN THE NEAR-INFRARED

We present infrared images of Cen A (NGC 5128) in the J, H, and K band s. The infrared morphology is primarily determined by the presence of a thin absorptive warped disk. By integrating the light of the underly ing prolate galaxy through such a disk, we construct models which we c ompare with infrared and X-ray data. The geometry of the warped disk n eeded to fit the IR data is consistent with a warped disk which has ev olved as a result of differential precession in a prolate potential. T he disk has an inclination, with respect to the principal axis of the underlying elliptical galaxy, that is higher at larger radii than in t he inner region. A scenario is proposed where a small gas-rich galaxy infalling under the force of dynamical friction is tidally stripped. S tripping occurs at different times during its infall. The orientation of the resulting gas disk depends upon the angular momentum of the inf alling galaxy. We find that the resulting precession angle of the disk is well described by the precession model, but that the inclination a ngle may vary as a function of radius. We propose an orbit for the inf alling galaxy that is consistent with the geometry of the warped disk needed to fit our infrared data, and rotation observed in the outer pa rt of the galaxy.