The broad wing of the [O III] λ5007 emission line in active galactic nuclei

Abstract

We use a sample of type 2 active galactic nuclei (AGNs) from SDSS DR7 in which the [O III] 5007 emission line can be modeled by two Gaussian components, a broad wing plus a narrow core, to investigate the origin of the broad wing and the connection between the velocity shift of the broad wing and the physical parameters of AGNs, as well as their host galaxies. We find that the flux of the wing components is statistically roughly equal to that of the core components. However, the velocity shift of the wing component has only weak, if any, correlations with the physical properties of AGNs and the host galaxies, such as bolometric luminosity, the Eddington ratio, the mass of supermassive black holes, D4000, HδA or stellar mass. Comparing the velocity shift from our type 2 AGN sample to that from the type 1 sample in Zhang et al., we suggest that the [O III] broad wing originates from outflow. © 2014 National Astronomical Observatories of Chinese Academy of Sciences and IOP Publishing Ltd.