A relation between circumnuclear HI, dust, and optical cores in
  low-power radio galaxies
  From new observations and literature data we investigate the presence of HI,
dust, and optical cores in the central kiloparsec of low-power radio galaxies.
The goal of this pilot study is to identify physical relations between these
components, which can help us to study kinematics and feeding mechanisms in
future samples of active galaxies. Our results are consistent with neutral gas
being associated with dust on sub-kiloparsec scales. Objects that have HI
absorption always have significant amounts of dust in their host galaxy. If
there is no visible dust in the host galaxy, there is also no HI absorption.
The presence of an unresolved optical core correlates with the HI column
density, with the core being absent in high column density sources. This work
opens a path for studying the kinematics of cold material in the central
regions of active galaxies by combining information of HI absorption and
molecular lines. Consistent with previous work, we find no evidence for a
compact, parsec-scale obscuring torus in low-power radio galaxies.
