Abstract Details
| Name: Tapas Baug Affiliation: Kavli Institute for Astronomy and Astrophysics Conference ID: ASI2019_316 Title : Influence of stellar wind of Galactic Wolf-Rayet stars on parent molecular clouds Authors and Co-Authors : T. Baug (KIAA), L. K. Dewangan (PRL), D. K. Ojha (TIFR) Abstract Type : Oral Abstract Category : Stars, ISM and Galaxy Abstract : Wolf-Rayet (W-R) stars (>20 Msun) are at the intermediate phase of the evolution descended from their early O-type progenitors. They have the ability to influence their surrounding molecular gas for producing new generation of star formation through their high mass-loss rates and high speed stellar winds. They may develop wind-blown expanding shells of parsecs-to-ten-parsec scales with typical expansion velocities of a few km/s, and ``Collect and Collapse'' triggering process may occur at the boundary of expanding molecular shells. We investigate four Galactic sites associated with W-R stars using a multi-wavelength approach. Signature of the cavity in the parent molecular cloud is found by a trough in between two emission peaks in the 13CO spectrum constructed along all four W-R stars. Spectro-photometric distances of all W-R stars agree well with kinematic distances corresponding to velocities of troughs. Presence of expanding molecular shells with expansion velocities from 2-5 km/s is inferred by the presence of ring-like structures in the position-velocity (p-v) diagrams of 13CO data. Also, W-R stars are located towards the center of these structures in the p-v diagrams indicating them to be the primary driving sources. Estimation of pressure components reveals that the pressure due to stellar wind dominates over the radiation pressure by an order of magnitude, and has the ability to influence the molecular gas within ~10 pc. Active star formation is traced in all selected sites inferred by the presence of rich cluster of young stellar objects (YSOs) within 10 pc of the W-R stars. Generally, clusters of YSOs are found to be associated with dense C18O (or 13CO) molecular condensations. Details of this study will be presented in the talk. |