ALMA reveals a cloud-cloud collision that triggers star formation in
  N66N of the Small Magellanic Cloud
  We present the results of Atacama Large Millimeter/submillimeter Array (ALMA)
observation in $^{12}$CO(1-0) emission at 0.58 $\times$ 0.52 pc$^2$ resolution
toward the brightest HII region N66 of the Small Magellanic Cloud (SMC). The
$^{12}$CO(1-0) emission toward the north of N66 reveals the clumpy filaments
with multiple velocity components. Our analysis shows that a blueshifted
filament at a velocity range 154.4-158.6 km s$^{-1}$ interacts with a
redshifted filament at a velocity 158.0-161.8 km s$^{-1}$. A third velocity
component in a velocity range 161-165.0 km s$^{-1}$ constitutes hub-filaments.
An intermediate-mass young stellar object (YSO) and a young pre-main sequence
star cluster have hitherto been reported in the intersection of these
filaments. We find a V-shape distribution in the position-velocity diagram at
the intersection of two filaments. This indicates the physical association of
those filaments due to a cloud-cloud collision. We determine the collision
timescale $\sim$ 0.2 Myr using the relative velocity ($\sim$ 5.1 km s$^{-1}$)
and displacement ($\sim$ 1.1 pc) of those interacting filaments. These results
suggest that the event occurred at about 0.2 Myr ago and triggered the star
formation, possibly an intermediate-mass YSO. We report the first observational
evidence for a cloud-cloud collision that triggers star formation in N66N of
the low metallicity $\sim$0.2 Z$_{\odot}$ galaxy, the SMC, with similar
kinematics as in N159W-South and N159E of the Large Magellanic Cloud.
