Investigation of high-quality spectra of a sample of high-radial-velocity stars
Abstract
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. 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. 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 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 MyGIsFOS galpy pipeline applying the Galactic potential MWPotential2014, in order to classify the stars kinematically. The stars span a wide metallicity range (-1.2 łesssim łesssim -2.9) and exhibit kinematic properties consistent with the outer halo population. Star C0213360-505024, Fe/H 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.
Related
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- The GAPS programme at TNG. LXXIX. New mass constraints for the infant planets in the V1298,Tau system through a long-term radial-velocity monitoring with HARPS-N
- The Long-Term Radial Velocity Stability of the COS G130M/1291 Mode
BibTeX
@article{alazzawi2026investigation,
title = {{Investigation of high-quality spectra of a sample of high-radial-velocity stars}},
author = {J. Alazzawi and E. Caffau and P. Bonifacio and S Çaliskan and L. Monaco and L. Sbordone and L. Lombardo},
journal = {Astronomy \& Astrophysics - A\&A},
year = {2026},
month = jul,
doi = {10.1051/0004-6361/202659789},
url = {https://hal.science/hal-05739015v1},
note = {CC BY-SA 4.0},
}
RIS
TY - JOUR
TI - Investigation of high-quality spectra of a sample of high-radial-velocity stars
AU - J. Alazzawi
AU - E. Caffau
AU - P. Bonifacio
AU - S Çaliskan
AU - L. Monaco
AU - L. Sbordone
AU - L. Lombardo
PY - 2026
DA - 2026/07/15
JO - Astronomy & Astrophysics - A&A
DO - 10.1051/0004-6361/202659789
UR - https://hal.science/hal-05739015v1
AB - 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. 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. 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 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 MyGIsFOS galpy pipeline applying the Galactic potential MWPotential2014, in order to classify the stars kinematically. The stars span a wide metallicity range (-1.2 łesssim łesssim -2.9) and exhibit kinematic properties consistent with the outer halo population. Star C0213360-505024, Fe/H 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.
SN - 0004-6361
SN - 1432-0746
ER -