Presentation #404.13 in the session Stellar Populations & Evolution — iPoster Session.
Very Metal-Poor (VMP; [Fe/H] < -2.0) and Extremely Metal-Poor (EMP; [Fe/H] < -3.0) stars play a significant role in studying the chemical evolution history of the Milky Way. The SkyMapper Southern Survey (SMSS) recently derived photometric-metallicity estimates for over 24 million stars (Huang et al. 2022), identifying large numbers of VMP (~ 500,000) and EMP (~ 25,000) stars along with their rotational velocity (vΦ) using space motions derived from Gaia EDR3. Here we identify the primordial VMP/EMP disk in the metallicity versus vΦ plane from low resolution (R ~ 1800) spectra of a Value Added Catalog (VAC) from LAMOST DR8 (Wang et al. 2022). These findings should provide a better understanding of the chemical and dynamical properties of the first stars in the early Galaxy, and candidates for future high-resolution spectroscopic follow-up.
This work was supported in part from grant PHY 14-30152; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE), awarded by the US National Science Foundation.