22 citations · 58 across the 21 of their papers we have counts for
9 papers · 1 filter
The -Process Alliance: On J00101735, an Accreted, Chemically Unusual, Metal-poor Star with -process Enhancement
Zoe Hackshaw, Rana Ezzeddine, Shivani P. Shah +11
We present a detailed chemo-dynamical analysis of the chemically peculiar very metal-poor ([Fe/H]) Milky Way (MW) halo star, 2MASS J001017581735387 (hereafter J0…
Payne4GAIN: NLTE Corrections for Red Giants in Milky Way Mapper using H-Band Neural Network Emulators
Pierre Thibodeaux, Alexander P. Ji, Nicholas Storm +12
The majority of spectroscopic surveys assume local thermodynamic equilibrium (LTE) during the modeling of stellar spectra. This assumption begins to break down for luminous stars,…
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…
Evaluating Classifications of Extremely Metal-poor Candidates Selected from Gaia XP Spectra
Riley Thai, Andrew R. Casey, Alexander Ji +2
Extremely metal-poor stars are intrinsically rare, but emerging methods exist to accurately classify them from all-sky Gaia XP low-resolution spectra. To assess their overall accur…
A nearly pristine star from the Large Magellanic Cloud
Alexander P. Ji, Vedant Chandra, Selenna Mejias-Torres +28
The first stars formed out of pristine gas, causing them to be so massive that none are expected to have survived until today. If their direct descendants were sufficiently low-mas…
The R-Process Alliance: Hunting for gold in the near-UV spectrum of 2MASS J05383296-5904280
Terese T. Hansen, Ian U. Roederer, Shivani P. Shah +10
Context. Over the past few years, the -Process Alliance (RPA) has successfully carried out a search for stars that are highly enhanced in elements produced via the rapid neutron…
LAMOST J1010+2358 is not a Pair-Instability Supernova Relic
Pierre N. Thibodeaux, Alexander P. Ji, William Cerny +2
The discovery of a star formed out of pair-instability supernova ejecta would have massive implications for the Population III star initial mass function and the existence of stars…
The -Process Alliance: Detailed Composition of an -Process Enhanced Star with UV and Optical Spectroscopy
Shivani P. Shah, Rana Ezzeddine, Ian U. Roederer +8
We present a detailed chemical-abundance analysis of a highly -process enhanced (RPE) star, 2MASS J00512646-1053170, using high-resolution spectroscopic observations with $Hubbl…
Spectacular nucleosynthesis from early massive stars
Alexander P. Ji, Sanjana Curtis, Nicholas Storm +39
Stars formed with initial mass over 50 Msun are very rare today, but they are thought to be more common in the early universe. The fates of those early, metal-poor, massive stars a…