| Name: Ashish Kumar Maindola |
| Affiliation: Ahmedabad University |
| Conference ID: ASI2026_534 |
| Title: Parametrising Young Star Clusters in the Magellanic Bridge Using UVIT, Gaia, and VMC data |
| Abstract Type: Oral |
| Abstract Category: Stars, Interstellar Medium, and Astrochemistry in Milky Way |
| Author(s) and Co-Author(s) with Affiliation: Ashish Kumar Maindola(School of Arts and Sciences, Ahmedabad University, Ahmedabad—380009, India), Samyaday Choudhury(School of Arts and Sciences, Ahmedabad University, Ahmedabad—380009, India), Prasanta Kumar Nayak(Institute of Astrophysics, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, Chile), Dhanush S.R(Indian Institute of Astrophysics, 2nd Block Koramangala, Bangalore 560034, India) |
| Abstract: We investigate star cluster formation in the Magellanic Bridge using multiwavelength data from the UVIT/AstroSat, combined with astrometric and optical data from Gaia and near-infrared observations from the VMC survey. High angular-resolution (≈1.4’’) UV observations from the UVIT enable us to study individual hot, young, and massive stars (OB-type and A-type) and young star clusters (aged 100-300 Myrs or younger), at the distance of the Magellanic Clouds (50 to 60 kpc). In this work, we studied ≈ 75 star cluster candidates in five UVIT tiles with far-ultraviolet data (F148W) available for all tiles, and near-ultraviolet data (N242W) available for three tiles. These cluster candidates are identified by catalogues from literature, out of which 80 % of the candidates are non-parametrised, and some may not be clusters at all. We segregate bona fide clusters and probable star clusters from non-cluster candidates by analysing spatial stellar distributions in the UVIT, Gaia, and VMC data, and comparing the cluster region color-magnitude diagrams (CMDs) with their adjacent field region CMDs. To obtain reliable cluster memberships, we apply selection criteria based on Gaia parallaxes, proper motions, and photometric quality cuts from UVIT and Gaia data. To estimate the fundamental cluster parameters (age, metallicity, distance modulus, and extinction), we use UVIT and Gaia CMDs and employ an automated algorithm we developed. The algorithm uses a χ²-minimisation technique to identify the best-fitting isochrone models to the cluster sequence from a grid of PARSEC models. Only 10 % to 30 % of the cluster candidates exhibit spatial clustering, and CMD features consistent with genuine star clusters and possible clusters. We deploy our technique to estimate the parameters for the non-cluster stellar aggregates as well. The parameterisation of all stellar aggregates in the Bridge is essential to deciphering its formation history and morphology. |
