IAUS379: Dynamical Masses of Local Group Galaxies

The Large Magellanic cloud(LMC) and Small Magellanic cloud(SMC) are the nearest interacting dwarf galaxies in the local group. And Magellanic clouds(MCs) have had interactions with each other as well as with the Milky Way. These interactions have triggered star formation in both galaxies, resulting in the formation of star clusters. Thus a comprehensive analysis of cluster population in MCs could indicate the structural evolution due to galaxy mergers. Our aim is to understand the age dating, spatio-temporal map of cluster formation episodes, and trace the cluster kinematics as a function of age.
In this study, we used the GAIA DR3 data to characterise the cluster population in the MCs. The clusters in the MCs is obtained mostly from general catalogue given by Bica et al. (2020), and several other recent literature. We classified the clusters as isolated and merged based on projected sky coordinates. Around 2000 clusters were analyzed in our study based on a certain selection criteria. We used Gaia asynchronous query to bulk handle the cluster data from Gaia archive, after applying proper motion-parallax cut offs and faintness magnitude limit. We developed a statistical algorithm to remove filed stars from the cluster region. We used single to multiple comparison field regions and retrieved the most probable cluster members. Using Padova-Parsec stellar evolutionary models, we performed an iterative least square method to estimate the age and reddening of clusters that had sufficient members and a satisfactory fit of the isochrone. The spatio-temporal map of age and reddening was obtained for clusters in both clouds. We traced the cluster formation episodes at ~ 1.6 Gyr, 630 Myr, 310 Myr, and 80 Myr. The directional propagation of cluster formation is noted from the South to North of LMC over the time scale of 2.8 Gyr to 10 Myr. We are able to estimate the formation time of the LMC’s off-centered bar. Using the proper motion data of the members we also study the proper motion of the clusters with respect to the field population in both the Clouds.