Resolution of quasar images.

Thirteen low redshift (z approximately less than 0.6) quasars have been resolved on large-scale, sky-limited photographs, and the images were analyzed by digitally removing the plate background and the point-spread function defined by images of nearby field stars, having magnitudes comparable to those of the quasars. The nebulosities around the quasars were found to have an average metric diameter of approximately 90 + or - 30 kpc and an integrated absolute magnitude of approximately -21.8 + or - 0.8. An expression is presented for the average intensity profile of the underlying nebulosity. Correlations (between the isophotal diameters of the resolved nebulosity and quasar redshifts; and the integrated apparent magnitudes of the underlying nebulosity and isophotal diameters) indicate roughly constant diameters and surface brightnesses for the nebulosities associated with the quasars. The physical and statistical properties of the nebulosities surrounding the quasars support the hypothesis that quasars are the luminous nuclei of distant galaxies.