A chromosome map to unveil stellar populations with different magnesium abundances. The case of ω Centauri
Milone, A. P.; Cordoni, G.; Marino, A. F.; Dondoglio, E.; Lagioia, E. P.; Tailo, M.; Li, C.; Jang, S.; Carlos, M.; Renzini, A.
Italy, China, South Korea, Brazil
Abstract
Historically, photometry has been largely used to identify stellar populations [multiple populations (MPs)] in globular clusters (GCs) by using diagrams that are based on colours and magnitudes that are mostly sensitive to stars with different metallicities or different abundances of helium, carbon, nitrogen, and oxygen. In particular, the pseudo-two-colour diagram called chromosome map (ChM), allowed the identification and the characterization of MPs in about 70 GCs by using appropriate filters of the Hubble Space Telescope (HST) that are sensitive to the stellar content of He, C, N, O, and Fe.