EMISSION-LINE PROFILES OF AGNS AND QSOS

90 emission line profiles, constituting 30 Balmer lines and 55 forbidden and 5 other permitted lines, from 31 objects comprising of S1, S2, S3 classes of Seyfert galaxies, H II regions and QSOs, are analysed. A new mathematical representation of the profile is introduced by fitting the blue and red sides of the profile to Chebychev polynomials and the top to an inverted parabola. Parameters developed from these fittings are used to define indices of asymmetry and kurtosis. Asymmetry, kurtosis and FWHM are computed for all the profiles. Results show good correlation between FWHM and kurtosis. Forbidden lines are found to be narrower and peakier, while Balmer lines and other permitted lines are broader and flatter. Furthermore, all lines are predominantly blueward asymmetric, although some significant redward asymmetry is exhibited by, in particular, forbidden lines of the S2 class and Balmer lines of the S1 class. No correlation is shown between asymmetry and kurtosis, or between asymmetry and FWHM.