Abstract Details

Name: Sadhana Singh
Affiliation: ARIES
Conference ID: ASI2021_449
Title : A multi-band linear polarimetric study toward the cluster NGC 2345
Authors and Co-Authors : Sadhana Singh (Aryabhatta Research Institute of Observational Sciences), Jeewan C. Pandey (Aryabhatta Research Institute of Observational Sciences)
Abstract Type : Oral
Abstract Category : Stars, ISM and Galaxy
Abstract : To get the information about properties of the dust (such as: shape, size, alignment of grains and polarization efficiency of dust grains) associated with the interstellar matter (ISM), we are studying polarization due to ISM by selecting the open star cluster. According to Davis & Greenstein (1951), the polarization of starlight is caused by the selective extinction due to the elongated dust grains aligned in space possibly due to the magnetic field. As the grains are thought to align due to the local magnetic field, the observed polarization vectors will help to map the general geometry of the magnetic field. I would like to present a multi-band optical linear polarimetric study in the region of the cluster NGC 2345. Observations have been carried out using the ARIES imaging polarimeter mounted on the 104-cm telescope of Aryabhatta Research Institute of observational Sciences, Nainital, India. The polarization is found to be wavelength dependent. The foreground interstellar dust grains appear to be main source of linear polarization of starlight towards the direction of NGC 2345. The average value of position angle in V-band of 153 degree is found to be near to the direction of Galactic Parallel in the region, indicating that the dust grains in the direction are probably aligned by Galactic magnetic field. The maximum value of the degree of polarization is estimated to be 1.67% for members of the cluster using the Serkowski relation. The average value of wavelength corresponding to the maximum polarization of 0.55 micron indicates that the size distribution of dust grains in the line of sight is similar to that of the general interstellar medium. The existence of dust layer near 1.2 kpc is also identified in the line of sight of the cluster. We also approached towards membership based on polarimetric technique.