What is the source of the morphological types in the NED database? Is there a way to find out where the classifications for each galaxy came from?
A.: Many of the morphological types in NED come from the Third Reference Catalog of Bright Galaxies (RC3). This is essentially the same system as described in the RC2. Both of these texts should be available from your library. We have also added physical classifications from spectroscopy when available (e.g. “Sy1”, “BLLAC”, “HII”, and so forth). These and other classifications come from the literature, but are not yet specifically referenced. • Q.: The “Morphology” line of NED’s Basic Data sometimes contains abbreviations such as “BCD” and “Sbrst”. What exactly do these mean? A.: These are usually “standard” abbreviations, taken from the literature, for various sorts of nuclear activity in galaxies. Occasionally, they are simply descriptive abbreviations relating to the morphology of the galaxy. Here is a list: AGN active galactic nucleus BAL broad absorption line BEL broad emission line BBG Balmer-break galaxy BCDG blue compact dwarf galaxy BH black hole BLAGN broad-line active galact
A.: Many of the morphological types in NED come from the Third Reference Catalog of Bright Galaxies (RC3). This is essentially the same system as described in the RC2. Both of these texts should be available from your library. We have also added physical classifications from spectroscopy when available (e.g. “Sy1”, “BLLAC”, “HII”, and so forth). These and other classifications come from the literature, but are not yet specifically referenced. • Q.: The “Morphology” line of NED’s Basic Data sometimes contains abbreviations such as “BCD” and “Sbrst”. What exactly do these mean? A.: These are usually “standard” abbreviations, taken from the literature, for various sorts of nuclear activity in galaxies. Occasionally, they are simply descriptive abbreviations relating to the morphology of the galaxy. Here is a list: AGN active galactic nucleus BAL broad absorption line BEL broad emission line BBG Balmer-break galaxy BCDG blue compact dwarf galaxy BH black hole BLAGN broad-line active galact
