| 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 : | Saikhom Pravash1, Archana Soam1, B-G Andersson2
|
| Authors Affiliation: | 1 Saikhom Pravash, Archana Soam Affiliation (Indian Institute of Astrophysics, 2nd block, Koramangala, Bengaluru 560034, India)
2 B-G Andersson Affiliation (SOFIA Science Centre/USRA, NASA Ames Research Centre, M.S. N232-12, Moffett Field, CA 94035, USA |
| Mode of Presentation: | 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). |
