Study of Milli-Jansky Seyfert Galaxies with Strong Forbidden
  High-Ionization Lines Using the Very Large Array Survey Images
  We study the radio properties at 1.4 GHz of Seyfert galaxies with strong
forbidden high-ionization lines (FHILs), selected from the Sloan Digital Sky
Survey - a large-sized sample containing nearly equal proportion of diverse
range of Seyfert galaxies showing similar redshift distributions compiled by
Gelbord et al. (2009) using the Very Large Array survey images. The radio
detection rate is low, 49%, which is lower than the detection rate of several
other known Seyfert galaxy samples. These galaxies show low star formation
rates and the radio emission is dominated by the active nucleus with $\le$10%
contribution from thermal emission, and possibly, none show evidence for
relativistic beaming. The radio detection rate, distributions of radio power,
and correlations between radio power and line luminosities or X-ray luminosity
for narrow-line Seyfert 1 (NLS1), Seyfert 1 and Seyfert 2 galaxies are
consistent with the predictions of the unified scheme hypothesis. Using
correlation between radio and [O\,III]\,$\lambda$ \,5007\,\AA\ luminosities, we
show that $\sim$8% sample sources are radio-intermediate and the remaining are
radio-quiet. There is possibly an ionization stratification associated with
clouds on scales of 0.1-1.0 kpc, which have large optical depths at 1.4 GHz,
and it seems these clouds are responsible for free-free absorption of radio
emission from the core, hence, leading to low radio detection rate for these
FHIL-emitting Seyfert galaxies.
