We report molecular line and continuum observations toward one of the most massive giant molecular clouds ( GMCs ) , GMC-16 , in M33 using ALMA with an angular resolution of 0 \farcs 44 \times 0 \farcs 27 ( \sim 2 pc \times 1 pc ) .
We have found that the GMC is composed of several filamentary structures in ^ { 12 } CO and ^ { 13 } CO ( J = 2–1 ) .
The typical length , width , and total mass are \sim 50–70 pc , \sim 5–6 pc , and \sim 10 ^ { 5 } M _ { \odot } , respectively , which are consistent with those of giant molecular filaments ( GMFs ) as seen in the Galactic GMCs .
The elongations of the GMFs are roughly perpendicular to the direction of the galaxy ’ s rotation , and several H ii regions are located at the downstream side relative to the filaments with an offset of \sim 10–20 pc .
These observational results indicate that the GMFs are considered to be produced by a galactic spiral shock .
The 1.3 mm continuum and C ^ { 18 } O ( J = 2–1 ) observations detected a dense clump with the size of \sim 2 pc at the intersection of several filamentary clouds , which is referred to as `` hub-filament . " The first example of protostellar outflow in M33 also has been identified at the center of the clump .
We have successfully resolved the pc-scale local star formation activity in which the galactic scale kinematics may induce the formation of the parental filamentary clouds .