THE PHYSICS GRADUATE PROGRAM invites everyone to the seminar:
Detailed chrono-chemo-dynamics of seven metal-poor red giants from Kepler
Arthur Alencastro Puls
Research School of Astronomy and Astrophysics, Australian National University
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.
Date: November 26, 2021 – (friday) – Time: 10:15 a.m.
link to access the youtube channel: https://youtu.be/D1pIcDUoHds