We present results of ^ { 12 } CO ( J = 1–0 ) imaging observations of \object NGC 4567/4568 , a galaxy pair in a close encounter , with Atacama Large Millimetre/submillimetre Array .
For the first time , we find clear evidence of a molecular collision front whose velocity dispersion is 16.8 \pm 1.4 km s ^ { -1 } at the overlapping region owing to high spatial and velocity resolution .
By integrating over the velocity width that corresponds to the molecular collision front , we find a long filamentary structure with a size of 1800 pc \times 350 pc at the collision front .
This filamentary molecular structure spatially coincides with a dark-lane seen in R -band image .
We find four molecular clouds in the filament , each with a radius of 30 pc and mass of 10 ^ { 6 } M _ { \odot } ; the radii matching a typical value for giant molecular clouds and the masses corresponding to those between giant molecular clouds and giant molecular associations .
All four clouds are gravitationally bound .
The molecular filamentary structure and its physical conditions are similar to the structure expected via numerical simulation .
The filament could be a progenitor of super star clusters .