The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XX. Ages of Single and Multiple Stellar Populations in Seven Bulge Globular Clusters
| Autor: | Santi Cassisi, Enrico Vesperini, Leandro Kerber, Eduardo Luiz Damiani Bica, Domenico Nardiello, F. F. S. Maia, R. A. P. Oliveira, Mattia Libralato, Ata Sarajedini, Francesca D'Antona, Susana O. Souza, Anna F. Marino, Jonathan Anderson, Beatriz Barbuy, Giampaolo Piotto, Adriano Pietrinferni, Luigi R. Bedin, Sergio Ortolani, Alvio Renzini, E. P. Lagioia, Ivan R. King, Thomas M. Brown, Angeles Pérez-Villegas, R. P. van der Marel, Antonio Aparicio, Antonino Milone |
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| Přispěvatelé: | Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), BRA |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
010504 meteorology & atmospheric sciences
Red giant Globular star clusters Galactic bulge Metallicity FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Bulge 0103 physical sciences Cluster (physics) Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Physics Subgiant Astronomy and Astrophysics Astrophysics - Astrophysics of Galaxies Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science [SDU]Sciences of the Universe [physics] Astrophysics of Galaxies (astro-ph.GA) Globular cluster Halo Astrophysics::Earth and Planetary Astrophysics |
| Zdroj: | The Astrophysical Journal The Astrophysical Journal, 2020, 891, ⟨10.3847/1538-4357/ab6f76⟩ |
| ISSN: | 0004-637X 1538-4357 1538-3881 0004-6361 0067-0049 1538-3873 1082-4774 0726-3252 |
| Popis: | In the present work we analyzed seven globular clusters selected from their location in the Galactic bulge and with metallicity values in the range $-1.30\lesssim\rm{[Fe/H]}\lesssim-0.50$. The aim of this work is first to derive cluster ages assuming single stellar populations, and secondly, to identify the stars from first (1G) and second generations (2G) from the main sequence, subgiant and red giant branches, and to derive their age differences. Based on a combination of UV and optical filters used in this project, we apply the Gaussian mixture models to distinguish the multiple stellar populations. Applying statistical isochrone fitting, we derive self-consistent ages, distances, metallicities, and reddening values for the sample clusters. An average of $12.3\pm0.4$ Gyr was obtained both using Dartmouth and BaSTI (accounting atomic diffusion effects) isochrones, without a clear distinction between the moderately metal-poor and the more metal-rich bulge clusters, except for NGC 6717 and the inner halo NGC 6362 with $\sim 13.5$ Gyr. We derived a weighted mean age difference between the multiple populations hosted by each globular cluster of $41\pm170$ Myr adopting canonical He abundances; whereas for higher He in 2G stars, this difference reduces to $17\pm170$ Myr, but with individual uncertainties of $500$ Myr. 25 pages, 16 figures and 7 tables. Accepted for publication in ApJ |
| Databáze: | OpenAIRE |
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