Radio Galaxies, AGN and more
Other interesting classes of objects can be cross-identified from all-sky surveys at other wavelengths (e.g. X-ray clusters, X-ray AGN, ULIRGs…).
Radio galaxies: cross-identified from NVSS, FIRST, SUMSS, etc. - largest samples of radio galaxies with redshifts ? radio LF, radio galaxy evolution…
Active galaxies: use emission-line ratios to classify as AGN/star-forming galaxies…