22 papers
Sr and Ba yields of the First Generation(s) of stars: Constraints from metal-poor stars
Sarah Hughes, Anna Frebel, Xiaowei Ou +6
We present our chemical abundance analysis of ten new extremely metal-poor stars with $-4.05\leq\mbox{[Fe/H]}\leq-2.33$, based on high-resolution (R ) Magellan/MIKE spe…
Carbon Abundances in Metal-Poor Stars Reveal Distinct Galaxy and Star Formation Pathways in the Early Universe
Alexander Yelland, Anna Frebel, Xiaowei Ou +2
Carbon-enhanced metal-poor (CEMP; with and ) stars preserve information about early chemical enrichment, low-mass star formation, and th…
The \emph{R}-process Alliance: A Bright, Strongly \emph{R}-process-enhanced Extremely Metal-poor Star Observed with GHOST
Mohammad K. Mardini, Anna Frebel, Vinicius M. Placco +8
We present a detailed chemical-abundance and kinematic analysis of four extremely metal-poor (EMP; [Fe/H] ) stars identified from \textit{Gaia} BP/RP data in our ongoing…
The Metallicity Distribution of the Ultra-Faint Dwarf Galaxy Segue 1
Daisy Bissonette, Alexander P. Ji, Joshua D. Simon +6
Ultra-faint dwarf galaxies (UFDs, ) offer unique insights into early chemical evolution in low-mass systems. However, interpreting their metallicity distributio…
The -Process Alliance: The -Process Enhancement of Stars from Chemodynamically Tagged Groups in the Milky Way Halo
Jessica Merritt Agnos, Charli M. Sakari, Pedro Silva +9
As part of the ongoing work of the -Process Alliance (RPA), detailed abundance measurements of 29 heavy elements in three metal-poor stars, 2MASS J145929813852558, 2MASS J194…
The -Process Alliance: Actinide Abundances, Variation, and Evolution in Metal-Poor Stars
Shivani P. Shah, Rana Ezzeddine, Erika M. Holmbeck +11
The actinides, including thorium (Th), are the heaviest observable elements synthesized in the universe, holding clues to the extremes of the astrophysical and nuclear conditions o…