Three-dimensional dust geometry of the LMC HI ridge region as revealed
  by the IRSF/SIRIUS survey
  We present a new method to evaluate the dust extinction (AV) along the line
of sight using the InfraRed Survey Facility (IRSF) near-infrared (NIR) data of
the Large Magellanic Cloud (LMC) HI ridge region. In our method, we estimate an
AV value for each star from the NIR color excess and sort them from bluer to
redder in each line of sight. Using the percentile values of the sorted AV, we
newly construct the three-dimensional AV map. We compare the resultant AV map
with the total hydrogen column density N(H) traced by velocity-resolved HI and
CO observations. In the LMC HI ridge region, Fukui et al. (2017, PASJ, 69, L5)
find two velocity components and an intermediate velocity one bridging them.
Comparing our three-dimensional AV maps with N(H) maps at the different
velocities, we find that the dust geometry is consistent with the scenario of
the on-going gas collision between the two velocities as suggested in the
previous study. In addition, we find difference by a factor of 2 in AV/N(H)
between the two velocity components, which suggests that inflow gas from the
Small Magellanic Clouds (SMC) is mixed in this region. As a whole, our results
support the triggered star formation in 30 Doradus due to the large-scale gas
collision caused by tidal interaction between the LMC and the SMC.
