Abstract Details
| Name: GIREESH CHANDRA Affiliation: KUMAUN UNIVERSITY Conference ID: ASI2015_453 Title : Spatial and dynamical properties of Open Star Clusters NGC 2099 and NGC 6866 Authors and Co-Authors : H. C. Chandola Department of Physics, Kumaun University, Nainital Abstract Type : Poster Abstract Category : Stars, The Milky Way Galaxy and its neighbours Abstract : Keeping in view the fact that the Open Star Clusters (OSCs) are the ideal tracer of galactic evolution and star formation process, two important large OSCs, viz. NGC 2099 and NGC 6866, have been studied especially for estimating their parameters and the dynamical behavior. Using the radial density profiles of these clusters, the radii of NGC 2099 and NGC 6866 have been estimated as 18 and 21 arcmin respectively. Since, the field of view of each cluster is contaminated by a large number of field stars, the dynamical, statistical and CMRD approaches have been used for such field star separation and 1600 members in NGC 2099 and 1357 members in NGC 6866 have been found in the cleaned CMD. Using the spatio-kinematic probability criteria of membership determination, the said members (of each OSCs) have been divided into the groups of most probable, probable, likely and boundary-line members. Furthermore, among the said members, NGC 2099 and NGC 6866 have been shown to have (25 YSO, 20 VRS and 242 k-excess) and (16 YSO, 12 VRS and 128 k-excess) members respectively. The best fit isochrones in color-magnitude diagrams have been shown to provide the apparent distance-modulus, reddening and log-age parameters for NGC 2099 and NGC 6866 as (11.3 mag, 0.29 mag and 8.7) and (10.95 mag, 0.11 mag and 8.85) respectively. The TCD associated with the said clusters, have been used to compute the total-to-selective extinction ratio in the direction of cluster to compare with its normal value. The dynamical state of said clusters have also been investigated through mass-function, mass-segregation and the relaxation time. |