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We present a sample of 167 type 2 AGNs with double-peaked [O III] 4959,5007narrow emission lines, selected from the Seventh Data Release of the SloanDigital Sky Survey. The double-peaked profiles can be well modeled by twovelocity components, blueshifted and redshifted from the systemic velocity.Half of these objects have a more prominent redshifted component. In caseswhere the H-beta emission line is strong, it also shows two velocity componentswhose line-of-sight (LOS) velocity offsets are consistent with those of [OIII]. The relative LOS velocity offset between the two components is typicallya few hundred km/s, larger by a factor of ~ 1.5 than the line full width athalf maximum of each component. The offset correlates with the host stellarvelocity dispersion sigma*. The host galaxies of this sample showsystematically larger sigma*, stellar masses, and concentrations, and olderluminosity-weighted mean stellar ages than a regular type 2 AGN sample matchedin redshift, [O III] 5007 equivalent width and luminosity; they show nosignificant difference in radio properties. These double-peaked features couldbe due to narrow-line region kinematics, or binary black holes. The statisticalproperties do not show strong preference for or against either scenario, andspatially resolved optical imaging, spectroscopy, radio or X-ray followup areneeded to draw firm conclusions.

Type 2 AGNs with Double-Peaked [O III] Lines: Narrow Line Region Kinematics or Merging Supermassive Black Hole Pairs?