6 papers
The s-process at Subsolar Metallicity: Insights from High-Resolution Infrared Spectroscopy of Magellanic Cloud Planetary Nebulae
N. C. Sterling, M. G. Stephenson, Harriet L. Dinerstein +8
We present observations of 12 Magellanic Cloud planetary nebulae (PNe) obtained with the high-resolution near-infrared spectrometer IGRINS on Gemini South. In 10 targets we detect…
Predictions from -process AGB models of the isotopic variations of zirconium and neodymium for comparison to bulk meteorites
Maria Lugaro, Giulia C. Cinquegrana, Balázs Szányi +6
Bulk meteoritic data show isotopic variability of -neutron-capture (-process) origin in a several elements heavier than Fe. One peculiar feature is that the lighter -pr…
Constraining intrinsic S-type AGB masses and third dredge-up using pulsation
Y. L. Mori, A. I. Karakas, S. W. Campbell
The lowest mass at which the third dredge-up (TDU) occurs for thermally-pulsing asymptotic giant branch (TP-AGB) stars remains a key uncertainty in detailed stellar models. S-type…
Abundances of Rarely Detected s-process Elements Derived from the Ultraviolet Spectrum of the s-process-enhanced Metal-poor Star HD 196944
Ian U. Roederer, Vinicius M. Placco, Amanda I. Karakas +2
We present an analysis of the heavy-element abundances of HD 196944, a carbon-enhanced metal-poor (CEMP) star enriched with elements produced by the slow neutron-capture process (s…
Using Binary Population Synthesis to Examine the Impact of Binary Evolution on the C, N, O, and -Process Yields of Solar-Metallicity Low- and Intermediate-Mass Stars
Zara Osborn, Amanda I. Karakas, Alex J. Kemp +3
Asymptotic giant branch (AGB) stars play a significant role in our understanding of the origin of the elements. They contribute to the abundances of C, N, and approximately …
Beryllium: The smoking gun of a rejuvenated star
Anne Rathsam, Jorge Meléndez, Amanda I. Karakas
Context. The chemistry and Galactic velocity components of the star HD 65907 suggest that despite its young isochronal age of 5 Gyr, it is in fact a merger of two old Populat…