THE ORIGIN OF DOUBLE-PEAKED NARROW LINES IN ACTIVE GALACTIC NUCLEI. II. KINEMATIC CLASSIFICATIONS FOR THE POPULATION AT z < 0.1

Abstract

We present optical long-slit observations of the complete sample of 71 Type 2 active galactic nuclei (AGNs) with double-peaked narrow emission lines at z  < 0.1 in the Sloan Digital Sky Survey. Double-peaked emission lines are produced by a variety of mechanisms including disk rotation, kiloparsec-scale dual AGNs, and narrow-line region (NLR) kinematics (outflows or inflows). We develop a novel kinematic classification technique to determine the nature of these objects using long-slit spectroscopy alone. We determine that 86% of the double-peaked profiles are produced by moderate-luminosity AGN outflows, 6% are produced by rotation, and 8% are ambiguous. While we are unable to directly identify dual AGNs with long-slit data alone, we explore their potential kinematic classifications with this method. We also find a positive correlation between the NLR size and luminosity of the AGN NLRs ( R NLR ∝ L [ O III ] 0.21 ± 0.05 ), indicating a clumpy two-zone ionization model for the NLR.