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R-process enrichment from a single event in an ancient dwarf galaxy
Alexander P. Ji, Anna Frebel, Anirudh Chiti +1
Elements heavier than zinc are synthesized through the (r)apid and (s)low neutron-capture processes. The main site of production of the r-process elements (such as europium) has be…
The Chemical Abundances of Stars in the Halo (CASH) Project. III. A New Classification Scheme for Carbon-Enhanced Metal-poor Stars with S-process Element Enhancement
Julie K. Hollek, Anna Frebel, Vinicius M. Placco +4
We present a detailed abundance analysis of 23 elements for a newly discovered carbon-enhanced metal-poor (CEMP) star, HE 0414-0343, from the Chemical Abundances of Stars in the Ha…
High-resolution spectroscopy of extremely metal-poor stars in the least evolved galaxies: Bootes II
Alexander P. Ji, Anna Frebel, Joshua D. Simon +1
We present high-resolution Magellan/MIKE spectra of the four brightest confirmed red giant stars in the ultra-faint dwarf galaxy Bootes II (Boo II). These stars all inhabit the met…
Preserving chemical signatures of primordial star formation in the first low-mass stars
Alexander P. Ji, Anna Frebel, Volker Bromm
We model early star forming regions and their chemical enrichment by Population III (Pop III) supernovae with nucleosynthetic yields featuring high [C/Fe] ratios and pair-instabili…
The Caterpillar Project: A Large Suite of Milky Way Sized Halos
Brendan F. Griffen, Alexander P. Ji, Gregory A. Dooley +4
We present the largest number of Milky Way sized dark matter halos simulated at very high mass ( M/particle) and temporal resolution (5 Myrs/snapshot) don…
Segue 1 - A Compressed Star Formation History Before Reionization
David Webster, Anna Frebel, Joss Bland-Hawthorn
Segue 1 is the current best candidate for a "first galaxy", a system which experienced only a single short burst of star formation and has since remained unchanged. Here we present…