| Abstract : | Massive OB stars greatly impact the Galaxy structure, evolution, and next-generation star formation. However, the formation of most massive stars is not fully understood. In this context, we have carried out an analysis of multi-wavelength data of a star-forming complex W31. The W31 complex hosts two H II regions (i.e., G10.30-0.15 (hereafter, W31-N) and G10.15-0.34 (hereafter, W31-S)) powered by the clusters of O-type stars. Herschel submillimeter images suggest the presence of hub-filament systems (HFSs) towards W31-N and W31-S. Hubs are the highest density regions where several filaments converge; interstellar gas and dust funnel through the filaments towards these hubs. An analysis of the molecular line data reveals two cloud components in the direction of W31-S, which are also connected by a bridge feature in the velocity space. Furthermore, a complementary distribution is also evident toward W31-S. The locations of the massive stars are exclusively found toward the common zones of molecular cloud components. These findings favour the applicability of cloud-cloud collision (CCC) around 2 Myr ago in this site. However, the signatures of CCC in W31-N are not as promising as W31-S. Stellar feedback processes might have destroyed the footprints of CCC over time in W31-N. Overall, the CCC scenario seems to explain the birth of massive stars and the presence of central hubs in the W31 complex. In this talk, I will discuss the implication of CCC to explain the origin of massive stars and central hubs. |
