J. Baldwin, M. Phillips, R. Terlevich
tlooto Summary
Various emission-line intensity ratios are used to classify extragalactic object spectra into four categories based on excitation mechanisms.
Abstract
An investigation is made of the merits of various emission-line intensity ratios for classifying the spectra of extragalactic objects. It is shown empirically that several combinations of easily-measured lines can be used to separate objects into one of four categories according to the principal excitation mechanism: normal H II regions, planetary nebulae, objects photoionized by a power-law continuum, and objects excited by shock-wave heating. A two-dimensional quantitative classification scheme is suggested.
Citation format
BALDWIN, J.; PHILLIPS, M.; TERLEVICH, R. ERRATUM - CLASSIFICATION PARAMETERS FOR THE EMISSION-LINE SPECTRA OF EXTRAGALACTIC OBJECTS. PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 1981, 93: 817–817.