| Abstract : | Dust in the interstellar medium accounts for only 1% of the mass of the ISM, but because of its ubiquitous nature, it is an essential part of the Galaxy. Distant regions of the Galactic plane are obscured from view at optical wavelengths due to the extinction by intervening dust clouds. Another manifestation of the dust in the interstellar medium is the polarization of background starlight. It is assumed that asymmetric dust grains get aligned in the presence of the interstellar magnetic field, which causes the unpolarized background starlight to become partially plane-polarized. Hence, polarization is an excellent tool to study dust properties. Polarimetric data can also trace the magnetic field orientation in the plane-of-the-sky towards the diffuse ISM as well as dense star-forming regions.
Open clusters are good candidates to carry out the polarization observations because all the member stars have common properties such as distance, age, and proper motion. Linear polarization study of open clusters combined with the distance information from Gaia EDR3 can help obtain the membership probabilities and the dust distribution along the line of sight.
Here, we shall be discussing the polarimetric observations of open clusters using an EMCCD based polarimeter (EMPOL) on the 1.2m Mount Abu telescope. We present results from a distant (~4kpc), loosely bound, disintegrating open cluster, Czernik 3, present in the 2nd galactic quadrant of the Galaxy. |
