The Distribution of Local Metal-Poor Star Populations in the Prime of the Universe
A Blueprint for the Milky Way's Stellar Populations. III. Spatial Distributions and Population Fractions of Local Halo Stars
We analyze the observed spatial, chemical, and dynamical distributions of local metal-poor stars, based on photometrically derived metallicity and distance estimates along with proper motions from the gaia mission.Throughout the sample volume kpc (along the prime meridian) along the galactic prime meridian, we identify stellar populations with distinct properties in the metallicity versus rotational velocity space, and model their phase-space distributions.Our decomposition provides refined positions of individual populations in this phase space identified in the previous papers of this series.Stars associated with the galactic center exhibit a larger proportion of metal-poor stars at greater distances from the galactic center with a slope of dex.This observed trend, along with a mild anti-correlation of a mean rotational velocity with metallicity km implies that more metal-rich stars in the inner region of the gse progenitor were gradually stripped away, while the prograde orbit of the merger at infall became radialized by dynamical friction.The metal-weak thick disk shows a similar spatial distribution as the splash, suggesting earlier dynamical heating of stars in the primordial disk of the milky way.
