Abstract Details
| Name: SAIKHOM PRAVASH SINGH Affiliation: Indian Institute of Astrophysics, Bangalore Conference ID: ASI2024_742 Title : Polarisation efficiencies of Bright-Rimmed Clouds and Cometary Globules Authors and Co-Authors : Saikhom Pravash1, Archana Soam1, B-G Andersson2 Abstract Type : Poster Abstract Category : Stars, Interstellar Medium, and Astrochemistry in Milky Way Abstract : The study of dust polarization (P) of background star lights after passing through the dust distribution in molecular clouds in the interstellar medium helps us to know about the dust grain properties and to trace the plane-of -the-sky component of the ISM magnetic field. Radiative Torque Alignment (RAT) is found to be most successful theory to understand interstellar dust grain alignment. In this work, we used optical polarization measurements towards nine of cometary globules (CGs) to study dust grain alignment in these reasons. We used distance (d) and extinction (Av) values from Gaia DR3 and StarHorse2 Catalog towards these regions. We estimated the polarization efficiencies (P/Av) and their relations with Av. We studied the variations of polarization properties as a function of Av and d of the stars projected towards these clouds. We find enhancement of Av with distance signifying presence of dust extinction layers at different distances. A drop in P/Av values is seen with Av. This suggest that grain alignment lowers as we go to higher densities. The drop in P/Av has a range of slopes from - 0.38 to -0.84. Our results are consistent to the predictions of RAT theory and agrees with the previous work on Local Bubble wall (Medan et al. 2019) and Sh2-185 region (Soam et al. 2021a). |