Optical Linear Polarization Study toward Czernik 3 Open Cluster at Different Spatial Scales

• Published in: The Astronomical journal 2022-08, Vol.164 (2), p.31
• Main Authors: Uppal, Namita, Ganesh, Shashikiran, Bisht, D.
• Format: Article
• Language: English
• Subjects: Astrometry; Astronomy; Clusters; Dust; Dust content; Interstellar dust extinction; Interstellar medium; Linear polarization; Milky Way disk; Open star clusters; Optical polarization; Polarization; Starlight polarization
• ISSN: 0004-6256; 1538-3881
• DOI: 10.3847/1538-3881/ac7445

We present the optical linear polarization observation of stars toward the core of the Czernik 3 cluster in the Sloan i band. The data were obtained using the EMPOL instrument on the 1.2 m telescope at Mount Abu Observatory. We study the dust distribution toward this cluster by combining the results from our polarization observations with the data from Gaia EDR3, WISE, and the H i , 12 CO surveys. In addition, we use the polarimetric data of previously studied clusters within 15° of Czernik 3 to understand the large-scale dust distribution. The observational results of Czernik 3 show a large range in the degree of polarization, indicating that the dust is not uniformly distributed over the plane of the sky, even on a small scale. The distance to Czernik 3 is constrained to 3.6 ± 0.8 kpc using the member stars in the core region identified from Gaia EDR3 astrometry. This makes it one of the most distant clusters observed for optical polarization so far. The variation of observed degree of polarization and extinction toward this cluster direction suggests the presence of at least two dust layers along this line of sight at distances of ∼1 and ∼3.4 kpc. There is an indication of the presence of dust in the center of the cluster as seen from an increase in the degree of polarization and WISE W4 flux. The large-scale distribution of dust reveals the presence of a region of low dust content between the Local Arm and the Perseus arm.