2025/11/02 by M. Navabi, Navabi, M., R. Carrera +5
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2511.00913
openalex publication_date 2025/11/02 · openalex created_date 2025/11/06 · openalex updated_date 2026/07/28
Taking advantage of the near-infrared calcium triplet lines, we determine metallicities for a sample of more than 3,500 red giant stars in the field of the Small Magellanic Cloud (SMC). We find a median metallicity of [Fe/H]=-1.05±0.01 dex with a negative metallicity gradient of -0.064±0.007 dex deg-1 between 1.2°~to 6.0°consistent with an outside-in evolution scenario. For the first time, we detect hints of a positive metallicity gradient within 1.2°, likely reflecting radial migration or centralised chemical enrichment. Azimuthal metallicity asymmetries are detected, with flatter gradients in the eastern and southern quadrants and steeper ones in the north and west. They are consistent with tidal interaction effects from the Large Magellanic Cloud (LMC). Finally, in spite of a clear distance and velocity bifurcations in the east, they seem to share a common chemical origin, in agreement with other studies.