Статья

The <i>Gaia</i>-ESO Survey: empirical estimates of stellar ages from lithium equivalent widths (<scp>eagles</scp>)

R. D. JeffriesAstrophysics Group, Keele University , Keele, Staffordshire ST5 5BG, UKR. J. JacksonAstrophysics Group, Keele University , Keele, Staffordshire ST5 5BG, UKN. J. WrightAstrophysics Group, Keele University , Keele, Staffordshire ST5 5BG, UKG WeaverAstrophysics Group, Keele University , Keele, Staffordshire ST5 5BG, UKG. GilmoreInstitute of Astronomy, University of Cambridge , Madingley Road, Cambridge CB3 0HA, UKS. RandichINAF – Osservatorio Astrofisico di Arcetri , Largo E. Fermi 5, I-50125 Florence, ItalyA. BragagliaINAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna , via Gobetti 93/3, I-40129 Bologna, ItalyA. J. KornObservational Astrophysics, Division of Astronomy and Space Physics, Department of Physics and Astronomy, Uppsala University , Box 516, SE-751 20 Uppsala, SwedenR. SmiljanićNicolaus Copernicus Astronomical Center, Polish Academy of Sciences , ul. Bartycka 18, PL-00-716 Warsaw, PolandK. BiazzoINAF – Osservatorio Astrofisico di Catania , via S. Sofia 78, I-95123 Catania, ItalyAndrew R. CaseyMonash Centre for Astrophysics, School of Physics & Astronomy, Monash University , Clayton 3800, Victoria, AustraliaA. FrascaINAF – Osservatorio Astrofisico di Catania , via S. Sofia 78, I-95123 Catania, ItalyA. GonneauInstitute of Astronomy, University of Cambridge , Madingley Road, Cambridge CB3 0HA, UKG. GuiglionLeibniz-Institut für Astrophysik Potsdam (AIP) , An der Sternwarte 16, D-14482 Potsdam, GermanyL. MorbidelliINAF – Osservatorio Astrofisico di Arcetri , Largo E. Fermi 5, I-50125 Florence, ItalyL. PrisinzanoINAF – Osservatorio Astronomico di Palermo , Piazza del Parlamento 1, I-90134 Palermo, ItalyG. G. SaccoINAF – Osservatorio Astrofisico di Arcetri , Largo E. Fermi 5, I-50125 Florence, ItalyG. TautvaiśienėInstitute of Theoretical Physics and Astronomy, Vilnius University , Sauletekio av. 3, 10257 Vilnius, LithuaniaC C WorleyINAF – Osservatorio Astrofisico di Arcetri , Largo E. Fermi 5, I-50125 Florence, ItalyS. ZaggiaINAF – Padova Observatory , Vicolo dell’Osservatorio 5, I-35122 Padova, Italy

2023en

ABI

Аннотация

ABSTRACT We present an empirical model of age-dependent photospheric lithium depletion, calibrated using a large homogeneously analysed sample of 6200 stars in 52 open clusters, with ages from 2 to 6000 Myr and −0.3 &lt; [Fe/H] &lt; 0.2, observed in the Gaia-ESO spectroscopic survey. The model is used to obtain age estimates and posterior age probability distributions from measurements of the Li i 6708 Å equivalent width for individual (pre) main-sequence stars with 3000 &lt; Teff/K &lt; 6500, a domain where age determination from the HR diagram is either insensitive or highly model-dependent. In the best cases, precisions of 0.1 dex in log age are achievable; even higher precision can be obtained for coeval groups and associations where the individual age probabilities of their members can be combined. The method is validated on a sample of exoplanet-hosting young stars, finding agreement with claimed young ages for some, but not others. We obtain better than 10 per cent precision in age, and excellent agreement with published ages, for seven well-studied young moving groups. The derived ages for young clusters (&lt;1 Gyr) in our sample are also in good agreement with their training ages, and consistent with several published model-insensitive lithium depletion boundary ages. For older clusters, there remain systematic age errors that could be as large as a factor of 2. There is no evidence to link these errors to any strong systematic metallicity dependence of (pre) main-sequence lithium depletion, at least in the range −0.29 &lt; [Fe/H] &lt; 0.18. Our methods and model are provided as software – ‘Empirical AGes from Lithium Equivalent widthS’ (eagles).

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Идентификаторы

DOI: 10.1093/mnras/stad1293

Цитирования и источники

Цитирований: 2Использованных источников: 0

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