8 papers
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,…
Evidence for elemental diffusion in the eclipsing binary star AI Phoenicis
Pierre F. L. Maxted, Nicholas Storm, Andreas J. Korn +7
AI Phe is an eclipsing binary star with an orbital period of 24.6 days for which the surface gravity and effective temperature are known from direct measurements to very high preci…
Observational constraints on the origin of the elements. X. Combining NLTE and machine learning for chemical diagnostics of 4 million stars in the 4MIDABLE-HR survey
Nicholas Storm, Maria Bergemann, Tomasz RóżaÅski +9
We present the 4MOST-HR resolution Non-Local Thermal Equilibrium (NLTE) Payne artificial neural network (ANN), trained on new FGK spectra with 16 elements computed in NL…
A method to derive self-consistent NLTE astrophysical parameters for 4 million high-resolution 4MOST stellar spectra in half a day with invertible neural networks
Victor F. Ksoll, Nicholas Storm, Maria Bergemann +5
Modern spectroscopic surveys obtain spectra for millions of stars. However, classical spectroscopic methods can often be computationally expensive, rendering them impractical for t…
Testing stellar yield prescriptions in OMEGA+: Implications for rising sodium abundances in young thick disc stars
Evans K. Owusu, Ashley J. Ruiter, Alex J. Kemp +8
We recently identified an upturn in [Na/Fe] for the population of Solar-type stars in the Galactic young thick disc () at super-Solar metallicity in…
M3DIS -- A grid of 3D radiation-hydrodynamics stellar atmosphere models for stellar surveys. II. Carbon-enhanced metal-poor stars
Philipp Eitner, Maria Bergemann, Richard Hoppe +6
Understanding the origin and evolution of carbon-enhanced metal-poor (CEMP) stars is key to tracing the Galaxy's early chemical enrichment. We investigate how realistic 3D radiatio…