| Issue |
A&A
Volume 688, August 2024
|
|
|---|---|---|
| Article Number | A180 | |
| Number of page(s) | 14 | |
| Section | Stellar structure and evolution | |
| DOI | https://doi.org/10.1051/0004-6361/202450344 | |
| Published online | 23 August 2024 | |
The HST Large Programme on ω Centauri
VI. The radial gradient of the stellar populations⋆
1
Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Giuseppe Saragat 1, Ferrara 44122, Italy
2
Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova 35122, Italy
e-mail: michele.scalco@inaf.it
3
Department of Astronomy, Indiana University, Swain West, 727 E. 3rd Street, Bloomington, IN 47405, USA
Received:
12
April
2024
Accepted:
29
May
2024
In this paper we present the analysis of Hubble Space Telescope (HST) observations of the globular cluster Omega Centauri. Our analysis combines data obtained in this work with previously published HST data from an earlier article of this series and encompasses a broad portion of the cluster’s radial extension. Our findings reveal a significant radial variation in the fraction of stars within the two largest stellar populations, showing that one of the main second-population groups (referred to as the blue main sequence (bMS) group) is more centrally concentrated than the first-population group (referred to as the red main sequence (rMS) group). Additionally, we explore the spatial variations of the other, smaller stellar populations (referred to as MSa and MSd) and find a qualitatively similar, but weaker, radial decrease in the fraction of stars in these populations at larger distances from the cluster centre. Only one of the populations identified (MSe) does not show any significant radial variation.
Key words: techniques: photometric / Hertzsprung-Russell and C-M diagrams / globular clusters: individual: NGC5139
The supplementary data are available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/688/A180
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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