Publications (12)
Solar carbon abundance from 3D non-LTE modelling of the diagnostic lines of the CH molecule
Richard Hoppe, Maria Bergemann, Philipp Eitner +5
The spectral lines of the CH molecule are a key carbon (C) abundance diagnostic in FGKM-type stars. These lines are detectable in metal-rich and, in contrast to atomic C lines, als…
NLTE modelling of integrated light spectra. Abundances of barium, magnesium, and manganese in a metal-poor globular cluster
Philipp Eitner, Maria Bergemann, Soeren Larsen
We study the effects of non-local thermodynamic equilibrium (NLTE) on the abundance analysis of barium, magnesium, and manganese from integrated light spectroscopy, as typically ap…
Detailed chemical composition of the globular cluster Sextans A GC-1 on the outskirts of the Local Group
Anastasia Gvozdenko, Søren S. Larsen, Michael A. Beasley +4
The chemical composition of globular clusters (GCs) across the Local Group provides information on chemical abundance trends. The host galaxy, Sextans A, is a low-surface-brightnes…
Observational constraints on the origin of the elements. III. Evidence for the dominant role of sub-Chandrasekhar SN Ia in the chemical evolution of Mn and Fe in the Galaxy
Philipp Eitner, Maria Bergemann, Camilla Juul Hansen +4
The abundance ratios of manganese to iron in late-type stars across a wide metallicity range place tight constraints on the astrophysical production sites of Fe-group elements. In…
M3DIS -- A grid of 3D radiation-hydrodynamics stellar atmosphere models for stellar surveys
Philipp Eitner, Maria Bergemann, Richard Hoppe +3
Large-scale stellar surveys, such as SDSS-V, 4MOST, WEAVE, and PLATO, require accurate atmospheric models and synthetic spectra of stars for accurate analyses of fundamental stella…
Observational constraints on the origin of the elements. I. 3D NLTE formation of Mn lines in late-type stars
Maria Bergemann, Andrew J. Gallagher, Philipp Eitner +9
Manganese (Mn) is a key Fe-group elements, commonly employed in stellar population and nucleosynthesis studies to explore the role of SN Ia. We have developed a new non-local therm…
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…
Planet formation throughout the Milky Way: Planet populations in the context of Galactic chemical evolution
Jesper Nielsen, Matthew Raymond Gent, Maria Bergemann +2
As stellar compositions evolve over time in the Milky Way, so will the resulting planet populations. In order to place planet formation in the context of Galactic chemical evolutio…
Observational constraints on the origin of the elements. IX. 3D NLTE abundances of metals in the context of Galactic Chemical Evolution Models and 4MOST
Nicholas Storm, Maria Bergemann, Philipp Eitner +8
Historically, various methods have been employed to understand the origin of the elements, including observations of elemental abundances which have been compared to Galactic Chemi…
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…
The Prince and the Pauper: Evidence for the early high-redshift formation of the Galactic -poor disc population
Matthew Raymond Gent, Philipp Eitner, Aldo Serenelli +5
Context. The presence of [/Fe]-[Fe/H] bi-modality in the Milky Way disc has animated the Galactic archaeology community since more than two decades. Aims. Our goal is to invest…