http://arxiv.org/abs/1909.04262
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\farcs44 $\times$ 0\farcs27 ($\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$\;${\sc 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.
K. Tokuda, K. Muraoka, H. Kondo, et. al.
Wed, 11 Sep 19
86/86
Comments: 11 pages, 4 figures, submitted to ApJ