The flux ratio of the [O III] λλ5007, 4959 lines in AGN: Comparison with theoretical calculations

Abstract

By taking into account the relativistic corrections to the magnetic dipole operator, the theoretical [O III] 5006.843/4958.911 line intensity ratio of 2.98 is obtained. In order to check this new value using the active galactic nuclei (AGN) spectra, we present the measurements of the flux ratio of the [OIII] λλ4959, 5007 emission lines for a sample of 62 AGN, obtained from the Sloan Digital Sky Survey (SDSS) data base and the published observations. We select only the high signal-to-noise ratio spectra for which the line shapes of the [O III] λλ4959,5007 lines are the same. We obtained an averaged flux ratio of 2.993 ± 0.014, which is in a good agreement with the theoretical one. © 2006 RAS.