DIFFRACTION-LIMITED 76-MAS SPECKLE MASKING OBSERVATIONS OF THE CORE OF NGC-1068 WITH THE SAO-6-M-TELESCOPE

We present the first K-band bispectrum speckle interferometry of NGC 1 068 with an angular resolution of 76 mas (similar to 5.5 pc). This ang ular resolution allows us to attribute the measured flux to only one o f the nuclear sources seen at radio wavelengths. The observed decreasi ng visibility function suggests that the dominant central core is prob ably not an unresolved point source, but slightly resolved with a FWHM diameter of similar to 30 mas similar to 2 pc for an assumed Gaussian intensity distribution. This 30 mas object is possibly the nuclear to rus and/or a scattering halo. We discuss different contributions to th e observed K band flux. Between 5 GHz and the K-band the spectrum of t his component is close to a nu(1/3) proportionality. In addition to th e standard interpretation of a hot dust torus surrounding the nucleus of NGC 1068, one cannot exclude the possibility that a sizeable fracti on of the nuclear flux reaches us via a scattering halo. This then wou ld allow us to determine physical parameters of the nuclear source.