Does the Narrow [O iii ] λ5007 Line Reflect the Stellar Velocity Dispersion in Active Galactic Nuclei?

Abstract

It has been proposed that the width of the narrow [O iii] 5007 emission line can be used as a surrogate for the stellar velocity dispersion in active galaxies. This proposition is tested using the Sloan Digital Sky Survey (SDSS) Early Data Release (EDR) spectra of 107 low-redshift radio-quiet QSOs and Seyfert 1 galaxies by investigating the correlation between black hole mass, as determined from HB FWHMand optical luminos- ity, and [O iii] FWHM. The correlation is real, but the scatter is large. Without additional information or selection criteria, the [O iii]width can predict the black hole mass to a factor of 5.