Results 1 to 10 of about 52,001 (350)

Elemental abundances in AGB stars and the formation of the Galactic bulge [PDF]

open access: diamondEPJ Web of Conferences, 2012
We obtained high-resolution near-IR spectra of 45 AGB stars located in the Galactic bulge. The aim of the project is to determine key elemental abundances in these stars to help constrain the formation history of the bulge.
Wood P.R.   +6 more
doaj   +2 more sources

The Missing Link: Testing Galactic Chemical Evolution Models with the First Multi-isotopic Abundances in Solar Twin Stars

open access: yesThe Astrophysical Journal, 2023
We present the first isotopic abundances of both ^13 CO and C ^18 O in solar twin stars and test the results against several galactic chemical evolution (GCE) models with different nucleosynthesis prescriptions.
David R. Coria   +5 more
doaj   +1 more source

Atomic Data Needs in Astrophysics: The Galactic Center “Scandium Mystery”

open access: yesAtoms, 2020
Investigating the Galactic center offers unique insights into the buildup and history of our Galaxy and is a stepping stone to understand galaxies in a larger context.
Brian Thorsbro
doaj   +1 more source

NLTE Analysis of High-Resolution H-Band Spectra, V: Neutral Sodium

open access: yesUniverse, 2023
In order to derive sodium abundances and investigate the effects of non-local thermodynamic equilibrium (NLTE) on the formation of H-band Na I lines, we update the sodium atomic model by incorporating collision rates with hydrogen from new quantum ...
Zeming Zhou   +6 more
doaj   +1 more source

Inhomogeneous Enrichment of Radioactive Nuclei in the Galaxy: Deposition of Live 53Mn, 60Fe, 182Hf, and 244Pu into Deep-sea Archives. Surfing the Wave?

open access: yesThe Astrophysical Journal, 2023
While modeling the galactic chemical evolution (GCE) of stable elements provides insights to the formation history of the Galaxy and the relative contributions of nucleosynthesis sites, modeling the evolution of short-lived radioisotopes (SLRs) can ...
Benjamin Wehmeyer   +5 more
doaj   +1 more source

The Chemical Enrichment of the Milky Way Disk Evaluated Using Conditional Abundances

open access: yesThe Astrophysical Journal, 2023
Chemical abundances of Milky Way disk stars are empirical tracers of its enrichment history. However, they capture joint-information that is valuable to disentangle.
Bridget L. Ratcliffe, Melissa K. Ness
doaj   +1 more source

Abundances of planetary nebulae in the Galactic bulge [PDF]

open access: yes, 2015
Context. Planetary nebulae (PNe) abundances are poorly known for those nebulae in the Galactic bulge. This is because of the high and uneven extinction in the bulge which makes visual spectral measurements difficult.
Asplund   +32 more
core   +2 more sources

Chemical Tracing and the Origin of Carbon in the Galactic Disk

open access: yesUniverse, 2022
A basic problem in studies of the evolution of chemical elements in galaxies is the uncertainties in the yields of elements produced by different types of stars.
Bengt Gustafsson
doaj   +1 more source

Neon and Sulfur Abundances of Planetary Nebulae in the Magellanic Clouds [PDF]

open access: yes, 2007
The chemical abundances of neon and sulfur for 25 planetary nebulae (PNe) in the Magellanic Clouds are presented. These abundances have been derived using mainly infrared data from the Spitzer Space Telescope.
Aller L. H.   +12 more
core   +4 more sources

The Abundance of S-Process Elements: Temporal and Spatial Trends from Open Cluster Observations

open access: yesUniverse, 2022
Spectroscopic observations of stars belonging to open clusters, with well-determined ages and distances, are a unique tool for constraining stellar evolution, nucleosynthesis, mixing processes, and, ultimately, Galactic chemical evolution.
Laura Magrini   +8 more
doaj   +1 more source

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