Images at 12.5 \mu m of nuclei of three nearby Seyfert galaxies — NGC 1275 , NGC 4151 and NGC 7469 — have been obtained with the Keck 10-m Telescope .
NGC 7469 is resolved and deconvolution delineates a structure ( < 0 . ^ { \prime \prime } 04 ) \times 0 . ^ { \prime \prime } 08 or < 13 \times 26 pc at a position angle of 135 \arcdeg .
From a comparison with structure seen at millimeter wavelengths , this structure is interpreted as a disk aligned with the molecular gas in the central few hundred parsecs of the galaxy .
NGC 1275 and NGC 4151 are not resolved ; limits on the sizes of these nuclei are 0 \farcs 08 and 0 \farcs 16 , corresponding to physical spatial scales of 28 and 10 pc .
The lower limits to the brightness temperatures implied by these size limits and the measured flux densities are within \sim 50 K of the 12 - 25 \mu m color temperatures of these systems as inferred from IRAS observations .
The angular size limits are within a factor of 2.5 of the sizes required to spatially resolve thermal emission from dust heated by a central luminosity source .
These sizes preclude significant contributions to the nuclear infrared emission from star forming regions .