Seminário com Arthur Alencastro Puls – 26 de novembro de 2021 (sexta-feira) – 10h15min
O PROGRAMA DE PÓS-GRADUAÇÃO EM FÍSICA convida para o seminário:
Detailed chrono-chemo-dynamics of seven metal-poor red giants from Kepler*
Arthur Alencastro Puls
Research School of Astronomy and Astrophysics, Australian National University
*Evento de presença obrigatória da disciplina seminários
Resumo:
The Kepler mission has yielded a revolution in the field of GalacticArchaeology, with its photometry allowing the determination of stellar parameters with an unprecedented level of precision for Red Giant stars. Recent studies have shown that a few of these objects display conflicting characteristics in the age-metallicity space (e.g., young and metal-poor). In this project we combine asteroseismic information from solar-like oscillations, high-resolution spectroscopy and Gaia astrometry to derive stellar ages, chemical abundances and kinematics for a group of metal-poor Red Giants, and characterise them in a multidimensional chrono-chemo-dynamical space. 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 RGB – mass-loss prescription. Two stars 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, such as Gaia-Sausage and Gaia-Sequoia, is discussed.
Data: 26 de novembro de 2021 – (sexta-feira) – Horário: 10h15min
Link de acesso ao canal do programa no youtube: https://youtu.be/D1pIcDUoHds
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