Speaker
Description
Massive stars release vast amounts of energy into the interstellar medium through their lifetime processes and supernova explosions, compressing nearby regions and triggering star formation. While triggering mechanisms have been studied on smaller scales, comprehensive analysis on a larger MilkyWay scale has been hindered by the lack of high-quality radio imaging and the limited angular resolution of molecular mapping. The significance of triggered star formation across the Galactic disc is, therefore, not well understood. This pilot study combines the SARAO MeerKAT Galactic Plane Survey (SMGPS) and the Structure, excitation, and dynamics of the inner Galactic interstellar medium (SEDIGISM) data to identify and examine molecular clouds associated with HII regions and supernovae remnants (SNRs). We focus on their physical properties and massive star formation potential. We identify 268 molecular clouds from the SEDIGISM tile that is found within the studied Galactic coordinate range in degrees (341≤𝑙 ≤343 and |𝑏|≤0.5), of which 159 clouds (∼60%) are associated with SMGPS extended sources. Compared to unassociated clouds, we find that associated clouds exhibit significantly higher mean mass (∼7000M⊙ vs. ∼1900 M⊙) and average gas surface density (∼88 M⊙/pc^2 vs. ∼66 M⊙/pc^2), but with slightly elevated virial parameters. We also find that the linewidth-size scaling relation reveals steeper scaling for associated clouds compared to unassociated clouds. These findings suggest an enhanced dynamical activity for the associated clouds and support the hypothesis that feedback from massive stars influences molecular cloud properties and may trigger star formation.
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