Investigation of high-quality spectra of a sample of high-radial-velocity stars
Year: 2026
Type: article
Abstract: Context . Old, metal-poor stars are perfect tracers of the formation of the Milky Way. The combination of chemical and kinematic investigations into them provides an insight into accretion episodes in the past history of our Galaxy. Aims . We present here a detailed chemical abundance analysis of 16 metal-poor stars, selected from the RAVE survey, which are characterised by a high radial velocity. Methods . We derived stellar parameters from Gaia photometry and parallaxes. Using high-resolution spectra obtained with UVES at the ESO-VLT, we determined elemental abundances for α -, iron-peak, and neutron-capture elements using the M Y GI S FOS pipeline. Departures from local thermodynamic equilibrium, where available, were investigated. We used the SPInS bayesian inference pipeline to derive ages for all the stars. Actions and other dynamical quantities were computed using the galpy pipeline applying the Galactic potential MWPotential2014, in order to classify the stars kinematically. Results . The stars span a wide metallicity range (−1.2 ≲ [Fe/H] ≲ −2.9) and exhibit kinematic properties consistent with the outer halo population. Star C0213360–505024, [Fe/H]=−1.4, appears to have an age of 1.3 Gyr and a mass of 1.6 M ⊙ . Based also on its kinematics and line broadening, which we attribute to stellar rotation, we argue that this star is young and not an evolved blue straggler. The available evidence points towards an accreted origin for this star and we speculate about its possible progenitor. The other 15 stars have ages compatible with an old population.
Source: Astronomy and Astrophysics
Institutions: Centre National de la Recherche Scientifique, Université Paris Cité, Université Paris Sciences et Lettres, Observatoire de Paris, Sorbonne Université, CY Cergy Paris Université, Ankara University, Universidad Andrés Bello, European Southern Observatory, European Southern Observatory, Trieste Astronomical Observatory, National Institute for Astrophysics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7168295393