Molecular gas kinematics in the nuclear region of nearby Seyfert
  galaxies with ALMA
  We present the analysis of the molecular gas in the nuclear regions of NGC
4968, NGC 4845, and MCG-06-30-15, with the help of ALMA observations of the
CO(2-1) emission line. The aim is to determine the kinematics of the gas in the
central (~ 1 kpc) region. We use the 3D-Based Analysis of Rotating Object via
Line Observations ($^{3D}$BAROLO) and DiskFit softwares. Circular motions
dominate the kinematics of the gas in the central discs, mainly in NGC 4845 and
MCG-06-30-15, however there is a clear evidence of non-circular motions in the
central ($\sim$ 1 kpc) region of NGC 4845 and NGC 4968. The strongest
non-circular motion is detected in the inner disc of NGC 4968 with velocity
$\sim 115\, \rm{km\,s^{-1}}$. The bisymmetric model is found to give the
best-fit for NGC 4968 and NGC 4845. If the dynamics of NGC 4968 is modeled as a
corotation pattern just outside of the bar, the bar pattern speed turns out to
be at $\Omega_b$ = $52\, \rm{km\,s^{-1}\,kpc^{-1}}$ the corotation is set at
3.5 kpc and the inner Lindblad resonance (ILR) ring at R = 300pc corresponding
to the CO emission ring. The 1.2 mm ALMA continuum is peaked and compact in NGC
4968 and MCG-06-30-15, but their CO(2-1) has an extended distribution. Allowing
the CO-to-H$_{2}$ conversion factor $\alpha_{CO}$ between 0.8 and 3.2, typical
of nearby galaxies of the same type, the molecular mass M(H$_{2}$) is estimated
to be $\sim 3-12\times 10^{7} ~{\rm M_\odot}$ (NGC 4968), $\sim 9-36\times
10^{7}~ {\rm M_\odot}$ (NGC 4845), and $\sim 1-4\times 10^{7}~ {\rm M_\odot}$
(MCG-06-30-15). We conclude that the observed non-circular motions in the disc
of NGC 4968 and likely that seen in NGC 4845 is due to the presence of the bar
in the nuclear region. At the current spectral and spatial resolution and
sensitivity we cannot claim any strong evidence in these sources of the long
sought feedback/feeding effect due to the AGN presence.
