oMEGACat. III. Multiband Photometry and Metallicities Reveal Spatially Well-mixed Populations within ω Centauri’s Half-light Radius
- Autor(en)
- 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
- Abstrakt
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(en)
- Institut für Astrophysik
- Externe Organisation(en)
- University of Utah, Max-Planck-Institut für Astronomie, Università degli Studi di Padova, Universidad Central de Chile, Space Telescope Science Institute, Georg-August-Universität Göttingen, Leibniz-Institut für Astrophysik Potsdam, Liverpool John Moores University (LJMU), INAF - Osservatorio Astronomico di Padova, Université de Strasbourg
- Journal
- The Astrophysical Journal
- Band
- 970
- Anzahl der Seiten
- 18
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.3847/1538-4357/ad5289
- Publikationsdatum
- 08-2024
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103003 Astronomie, 103004 Astrophysik
- Schlagwörter
- ASJC Scopus Sachgebiete
- Astronomy and Astrophysics, Space and Planetary Science
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/90908c9c-0ae5-42e3-a85b-7a25350ffbd3