6 papers
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…
Chemical Abundances in the Metal-Poor Globular Cluster ESO 280-SC06: A Formerly Massive, Tidally Disrupted Globular Cluster
Sam A. Usman, Alexander P. Ji, Jandrie Rodriguez +6
We present the first high-resolution abundance study of ESO 280-SC06, one of the least luminous and most metal-poor gravitationally bound Milky Way globular clusters. Using Magella…
Multiple Populations and a CH Star Found in the 300S Globular Cluster Stellar Stream
Sam A. Usman, Alexander P. Ji, Ting S. Li +14
Milky Way globular clusters (GCs) display chemical enrichment in a phenomenon called multiple stellar populations (MSPs). While the enrichment mechanism is not fully understood, th…
Detailed Chemical Abundance Analysis of the Brightest Stars in the Turranburra and Willka Yaku Stellar Streams
Kaitlin B. Webber, Terese T. Hansen, Jennifer L. Marshall +20
We present a detailed chemical abundance analysis of the three brightest known stars from each of the Turranburra and Willka Yaku stellar streams using high-resolution Magellan/MIK…
Chemical Abundances in the Leiptr Stellar Stream: A Disrupted Ultra-faint Dwarf Galaxy?
Kaia R. Atzberger, Sam A. Usman, Alexander P. Ji +11
Chemical abundances of stellar streams can be used to determine the nature of a stream's progenitor. Here we study the progenitor of the recently discovered Leiptr stellar stream,…
Flipping of the tidal tails of the Ophiuchus stream due to the decelerating Galactic bar
Yong Yang, Geraint F. Lewis, Denis Erkal +16
The Ophiuchus stellar stream presents a puzzle due to its complicated morphology, with a substructure perpendicular to the main track (spur), a broadened tail (fanning), and a shor…