oMEGACat. III. Multiband Photometry and Metallicities Reveal Spatially Well-mixed Populations within ω Centauri’s Half-light Radius
- Author(s)
- M. S. Nitschai, N. Neumayer, M. Häberle, C. Clontz, A. C. Seth, A. P. Milone, M. Alfaro-Cuello, A. Bellini, S. Dreizler, A. Feldmeier-Krause, T.-O. Husser, N. Kacharov, S. Kamann, M. Latour, M. Libralato, G. van de Ven, K. Voggel, Z. Wang
- Abstract
ω Centauri, the most massive globular cluster in the Milky Way, has long been suspected to be the stripped nucleus of a dwarf galaxy that fell into the Galaxy a long time ago. There is considerable evidence for this scenario including a large spread in metallicity and an unusually large number of distinct subpopulations seen in photometric studies. In this work, we use new Multi-Unit Spectroscopic Explorer spectroscopic and Hubble Space Telescope photometric catalogs to investigate the underlying metallicity distributions as well as the spatial variations of the populations within the cluster up to its half-light radius. Based on 11,050 member stars, the [M/H] distribution has a median of (−1.614 ± 0.003) dex and a large spread of ∼1.37 dex, reaching from −0.67 to −2.04 dex for 99.7% of the stars. In addition, we show the chromosome map of the cluster, which separates the red giant branch stars into different subpopulations, and analyze the subpopulations of the most metal-poor component. Finally, we do not find any metallicity gradient within the half-light radius, and the different subpopulations are well mixed.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- University of Utah, Max-Planck-Institut für Astronomie, University of Padova, Universidad Central de Chile, Space Telescope Science Institute, Georg-August-Universität Göttingen, Leibniz-Institut für Astrophysik Potsdam, Liverpool John Moores University (LJMU), Osservatorio Astronomico, Université de Strasbourg
- Journal
- The Astrophysical Journal
- Volume
- 970
- No. of pages
- 18
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.3847/1538-4357/ad5289
- Publication date
- 08-2024
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/90908c9c-0ae5-42e3-a85b-7a25350ffbd3