According to Zwicky [210], `compact' is a term that applies to ``any galaxy, or any part of a galaxy, whose surface brightness photographically, visually or bolometrically is greater than that which corresponds to m < 20 mag/arcsec2.'' Alternatively, Zwicky [209] also defined a compact galaxy as ``those which can just be distinguished from stars taken with the Palomar 48-inch telescope and which have diameters of 2-3 arcsec'', whereas moderately compact is invoked ``if its image, on photographs taken with the 18-inch Palomar Schmidt telescope can barely be distinguished from stars of the same apparent brightness. These systems have diameters of about 5 to 10 arcsec.'' Spectroscopic follow-up in [165].
Arakelian [2] lists 621 galaxies of high surface brightness, defined as having average surface brightnesses greater than 22 mag/arcsec2.
Click here to see the NED listing of Arakelian Galaxies.