54 citations · 161 across the 17 of their papers we have counts for
7 papers · 1 filter
Many elements matter: Detailed abundance patterns reveal star-formation and enrichment differences among Milky Way structural components
Emily J. Griffith, David W. Hogg, Sten Hasselquist +5
Many nucleosynthetic channels create the elements, but two-parameter models characterized by and Fe nonetheless predict stellar abundances in the Galactic disk to accuracies of…
The Milky Way Radial Metallicity Gradient as an Equilibrium Phenomenon: Why Old Stars are Metal-Rich
James W. Johnson, David H. Weinberg, Guillermo A. Blanc +12
Metallicities of both gas and stars decline toward large radii in spiral galaxies, a trend known as the radial metallicity gradient. We quantify the evolution of the metallicity gr…
Rising from the Ashes II: The Bar-driven Abundance Bimodality of the Milky Way
Angus Beane, James Johnson, Vadim Semenov +3
The Milky Way hosts at least two modes in its present day distribution of Fe and alpha-elements. The exact cause of this bimodality is disputed, but one class of explanations invol…
The APO-K2 Catalog. II. Accurate Stellar Ages for Red Giant Branch Stars across the Milky Way
Jack T. Warfield, Joel C. Zinn, Jessica Schonhut-Stasik +11
We present stellar age determinations for 4661 red giant branch stars in the APO-K2 catalog, derived using mass estimates from K2 asteroseismology from the K2 Galactic Archaeology…
Modeling the Galactic Chemical Evolution of Helium
Miqaela K. Weller, David H. Weinberg, James W. Johnson
We examine the galactic chemical evolution (GCE) of He in one-zone and multi-zone models, with particular attention to theoretical predictions and empirical constraints on IMF-…
Galactic Chemical Evolution Models Favor an Extended Type Ia Supernova Delay-Time Distribution
Liam O. Dubay, Jennifer A. Johnson, James W. Johnson
Type Ia supernovae (SNe Ia) produce most of the Fe-peak elements in the Universe and therefore are a crucial ingredient in galactic chemical evolution models. SNe Ia do not explode…
Nature vs. Nurture: Distinguishing Effects from Stellar Processing and Chemical Evolution on Carbon and Nitrogen in Red Giant Stars
John D. Roberts, Marc H. Pinsonneault, Jennifer A. Johnson +16
The surface [C/N] ratios of evolved giants are strongly affected by the first dredge-up (FDU) of nuclear-processed material from stellar cores. C and N also have distinct nucleosyn…