Abstract Details

Name: prasanta nayak
Affiliation: Tata institute of Fundamental Research, Mumbai, India
Conference ID: ASI2020_443
Title : Study of star cluster populations in the Magellanic Clouds
Authors and Co-Authors : Prasanta Kumar Nayak, Annapurni Subramaniam
Abstract Type : Oral
Abstract Category : Thesis
Abstract : In this study, we estimated parameters (age and reddening) of a large number of clusters to understand demographics of cluster formation and signatures of interactions using the Optical Gravitational Experiment III data. We developed a semi-automated method and parameterized more than 1200 clusters to produce two online catalogues. We also classified these clusters and grouped them into 5 groups, based on their mass/strength. In our sample, 90% of the SMC clusters and 80% of the LMC clusters studied here belong to the open cluster like the population in our Galaxy, with mass < 1700 M_sun, suggesting a similar population of clusters in these three galaxies. We found that both the clouds have gone through a recent burst of cluster formation at ∼125 Myr. We suggest the most recent interaction between the Clouds around 100-250 Myr could have triggered the cluster formation. We find evidence for outside to inside propagation of cluster formation in the LMC, whereas the cluster formation is found to propagate from South-West to North-east in the SMC. The bar region of the LMC is found to have formed clusters in the age range 60-250 Myr, suggesting that the LMC bar was active in the past. We have also studied an intermediate age rich star cluster (Kron 3), located in the southern SMC using multi-wavelength data from ultraviolet (UV) to infrared to study the stellar population in the cluster. The combined data from UVIT, HST, Gaia and VISTA help us to derive the radius of the cluster and identify an extended red clump (RC) population in the field de-contaminated CMD. Analysis using three different methods suggest that a large spread in metallicity among the RC stars as the possible reason for the extended RC population. Detailed high-resolution spectroscopic studies are needed to confirm this result.