Chemo-dynamics and asteroseismic ages of seven metal-poor red giants from the Kepler field

Arthur Alencastro Puls, Luca Casagrande, Stephanie Monty, David Yong, Fan Liu, Dennis Stello, Victor Aguirre Børsen-Koch, Ken C. Freeman

Research output: Contribution to journalArticleResearchpeer-review

4 Citations (Scopus)

Abstract

In this work, we combine information from solar-like oscillations, high-resolution spectroscopy, and Gaia astrometry to derive stellar ages, chemical abundances, and kinematics for a group of seven metal-poor red giants and characterize them in a multidimensional chrono-chemo-dynamical space. Chemical abundance ratios were derived through classical spectroscopic analysis employing 1D LTE atmospheres on Keck/HIRES spectra. Stellar ages, masses, and radii were calculated with grid-based modelling, taking advantage of availability of asteroseismic information from Kepler. The dynamical properties were determined with galpy using Gaia EDR3 astrometric solutions. Our results suggest that underestimated parallax errors make the effect of Gaia parallaxes more important than different choices of model grid or - in the case of stars ascending the red giant branch - mass-loss prescription. Two of the stars in this study are identified as potentially evolved halo blue stragglers. Four objects are likely members of the accreted Milky Way halo, and their possible relationship with known accretion events is discussed.

Original languageEnglish
Pages (from-to)1733-1747
Number of pages15
JournalMonthly Notices of the Royal Astronomical Society
Volume510
Issue number2
DOIs
Publication statusPublished - Feb 2022
Externally publishedYes

Keywords

  • Galaxy: abundances
  • Galaxy: kinematics and dynamics
  • stars: fundamental parameters

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