The Origin of Double-Peaked Narrow Lines in Active Galactic Nuclei I:
  Very Large Array Detections of Dual AGNs and AGN Outflows
  We have examined a subset of 18 active galactic nuclei (AGNs) drawn from a
sample of 81 galaxies that possess double-peaked narrow optical emission line
spectra in the Sloan Digital Sky Survey, have two optical AGN emission
components separated by >0.2", and are detected in the Faint Images of the
Radio Sky at Twenty-centimeters survey. Without follow-up observations, the
sources of the double-peaked narrow emission lines are uncertain, and may be
produced by kpc-scale separation dual active supermassive black holes, AGN
outflows, or disk rotation. In this work, we propose a new methodology to
characterize double-peaked narrow emission-line galaxies based on optical
long-slit spectroscopy and high resolution multi-band Very Large Array
observations. The nature of the radio emission in the sample galaxies is
varied. Of the 18 galaxies, we detect two compact flat-spectrum radio cores
with projected spatial separations on the sky between 0.6-1.6 kpc in three
galaxies: J1023+3243, J1158+3231, and J1623+0808. The two radio sources are
spatially coincident with the two optical components of ionized gas with
AGN-like line ratios, which confirms the presence of dual AGNs in these three
galaxies. Dual AGNs account for only ~15% (3/18) of the double-peaked AGNs in
our sample. Gas kinematics produce ~75% (13/18) of the double-peaked narrow
emission lines, distributed in the following way: 7 AGN wind-driven outflows, 5
radio-jet driven outflows, and one rotating narrow-line region. The remaining
~10% (2/18) are ambiguous cases. Our method demonstrates the power of spatially
resolved spectroscopy and high resolution radio observations for the
identification of AGN outflows and AGN pairs with angular separations as small
as 0.18".
