In rad m -2 . In nearly all cases this will be due to Faraday rotation in the interstellar medium of our Galaxy . LAS Largest Angular Size, in arcsec . Size, D Projected linear size, in kiloparsec . The name of the optical identification, if there is one.
Quasars are just luminous active galactic nuclei .
Thus the difference between galaxy and quasar is a matter of degree. On some definitions,galaxies with bright nuclei like 3C 109 and 3C 390.3 would qualify as quasars. These are the blended absorption lines of the stars in the galaxy. Often called a Seyfert 2 spectrum. Often called a Seyfert 1 spectrum.