H I Kinematics of the Large Magellanic Cloud revisited : Evidence of
  possible infall and outflow
  The neutral atomic Hydrogen (H I) kinematics of the Large Magellanic Cloud
(LMC) is revisited in light of two new proper motion estimates. We analysed the
intensity weighted H I velocity maps of the ATCA/Parkes and GASS data sets. We
corrected the line of sight velocity field for the systemic, transverse,
precession, and nutation motions of the disk using two recent proper motion
estimates, and estimated the kinematic parameters of the H I disk. The value of
position angle (PA) of kinematic major axis estimated using ATCA/Parkes data is
found to be similar to the recent estimate of the PA using stellar tracers. The
effect of precession and nutation in the estimation of PA is found to be
significant. Using ATCA/Parkes data, most of the H I gas in the LMC is found to
be located in the disk. We detected 12.1% of the data points as kinematic
outliers. We identified the well-known Arm E, Arm S, Arm W, Arm B and a new
stream, Outer Arm, as part of outlier components. The GASS data analysis brings
out the velocity details of the Magellanic Bridge (MB) and its connection to
the LMC disk. We find that the Arm B and the Outer Arm are connected to the MB.
We detect high velocity gas in the western disk of the LMC and the south-west
and southern parts of the MB. We proposed two models (in plane and out of
plane) to explain the outlier gas. We suggest that the Arm B could be an infall
feature, originating from the inner MB. The Arm E could be an outflow feature.
We suggest possible outflows from the western LMC disk and south and south
western MB, which could be due to ram pressure. The velocity pattern observed
in the MB suggests that it is being sheared. We suggest that the various
outliers identified in this study may be caused by a combination of tidal
effects and hydrodynamical effect due to the motion of the LMC in the Milky Way
(MW) halo.
