NGC 1068 is a barred galaxy with a very complex nuclear
region. Although it is an archetype Seyfert2, at least half of the IR emission
arises from star formation (Young, Kleinmann & Allen 1988). High-resolution
(2) VLA HI absorption measurements carried out by
Gallimore et al. (1994) reveal several blue- and red-shifted features against
the SW radio lobe and a jet as well as broad (FWHM = 12825 kms-1)
double absorption lines against the radio nucleus. The absorption lines cover
a total velocity range of 540 kms-1, from 760 to
1300 kms-1. The two lines against the core are centred at
+6612 kms-1 and -2959 kms-1, resulting in a mean
offset from
of -181 kms-1.
Because of this large offset Gallimore et al. reject circular orbits (which
are favoured for many of the galaxies presented here), but prefer a model
with two distinct, near-nuclear cloud populations, one falling into and the
other flowing out of the radio core, both associated with the fuelling of
and exhaust from the central engine. In case of a fast-rotating nuclear ring
I would expect the radius to coincide with the inner Lindblad resonance (ILR)
induced by the bar potential. It is possible that the absorption lines observed
in NGC 1068 are caused by outflow and a nuclear ring as suggested for NGC 253.
For comparison see also the summary of HI absorption measurements
against the Seyfert galaxy NGC 4151 and the peculiar galaxy NGC 4258 in
Section 4.3.
A detailed discussion of NGC 1068 and NGC 4151 is given in the chapter by
Brinks & Mundell in this volume.