The flux ratio of the [OIII] λ λ 4959, 5007 Å lines in AGN

Abstract

Up to now, all direct observational checks of the theoretical [OIII] 5006.843/4958.511 intensity ratio have been made for photoionized gaseous nebulae spectra. However, in some papers analyzing spectra of quasars, galaxies and AGN, this ratio is obtained as by-product, used as a checking method or may be derived from published results. Recently, taking into account relativistic corrections to the magnetic dipole operator, Storey and Zeippen obtained the line intensity ratio of 2.98. In order to check that new value using the AGN spectra, we present the measurements of flux ratio of [OIII] λ λ 4959, 5007 Å emission lines for a sample of 62 AGN, obtained from SDSS Database and from the published observations. We selected the sample using criteria of high signal to noise ratio and that line shapes of 4959 and 5007 are the same. We found that flux ratio is 2.993 ± 0.014, which is in a good agreement with the theoretical value of 2.98 given by Storey and Zeippen (2000). © 2007 American Institute of Physics.