| Name: Jatin Tekani |
| Affiliation: Ahmedabad University |
| Conference ID: ASI2026_240 |
| Title: Photometric Metallicity Map estimation of the SMC using Gaia DR3 |
| Abstract Type: Poster |
| Abstract Category: Galaxies and Cosmology |
| Author(s) and Co-Author(s) with Affiliation: Jatin Tekani(Ahmedabad University, Ahmedabad—380009, India), Samyaday Choudhury(Ahmedabad University, Ahmedabad—380009, India) |
| Abstract: Metallicity maps and the estimation of radial metallicity gradients are essential for understanding the chemical evolution and formation history of galaxies. Due to its proximity, low metallicity, well-resolved stellar populations, and a history of interaction with the Large Magellanic Cloud and the Milky Way, the Small Magellanic Cloud (SMC) provides an excellent environment for studying the constraints on dwarf galaxy evolution and interaction-driven chemical enrichment. Photometric metallicity indices derived from large-area sky surveys of the SMC, calibrated with spectroscopic data provide an advantage of covering large radial distances (≳ 5 degrees) to estimate high-spatial resolution (≈ 9 x 9 square arcmin or 150 x 150 square parsec) metallicity maps, and radial metallicity gradients from the central region (bar) to outer peripheries that host critical signatures of its interaction history. In this work, we utilise the curvature of the red giant branch (RGB) identified in the Gaia DR3 colour-magnitude diagram (CMD) of small regions in the SMC as an indicator of the mean metallicity of that region. We adapt earlier approaches on photometric metallicity maps in terms of identifying RGB stars in this galaxy from the CMD, use parallax and proper motion and photometric quality cuts and offer improvement in estimating its curvature using a least-squares fit technique, while aiming to correct for the effects of reddening and age variations on metallicity estimates compared with past studies. We calibrate the photometric indices (RGB curvature) using [Fe/H] estimates from Gaia DR3-XP low-resolution spectra and archival spectroscopic data. We will highlight the technique and some of the findings from this ongoing study. |
