Results 1 to 10 of about 50,982 (241)

Stellar Iron Abundances at the Galactic Center [PDF]

The Astrophysical Journal, 2000
We present measurements of [Fe/H] for six M supergiant stars and three giant stars within 0.5 pc of the Galactic Center (GC) and one M supergiant star within 30 pc of the GC. The results are based on high-resolution (lambda / Delta lambda =40,000) K-band
Solange Ramírez, K. Sellgren, J. Carr, S. Balachandran, Robert Blum, D. M. Terndrup, Adam Steed   +6 more
core   +10 more sources

Galactic abundances: Report of working group 3 [PDF]

, 2001
We summarize the various methods and their limitations and strengths to derive galactic abundances from in-situ and remote-sensing measurements, both from ground-based observations and from instruments in space. Because galactic abundances evolve in time
B. Klecker
openalex   +4 more sources

Abundances of planetary nebulae in the Galactic bulge [PDF]

Astronomy & Astrophysics, 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, Chiappini, Cuisinier, Escudero, Exter, Gorny, Gorny, Gorny, Gutenkunst, Henry, Houck, Hummer, J. Bernard-Salas, Kingsburgh, Lebouteiller, Maciel, Marigo, Martín-Hernández, Mokiem, Perea-Calderon, Pottasch, Pottasch, Pottasch, Rudolph, S. R. Pottasch, Sahai, Sellwood, Shaver, Stanghellini, Surendiranath, Surendiranath, Wang, Webster   +32 more
core   +6 more sources

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

The 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, Ian J. M. Crossfield, Joshua Lothringer, Becky Flores, Nikos Prantzos, Richard Freedman   +5 more
doaj   +1 more source

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

Atoms, 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

Universe, 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, Jianrong Shi, Shaolan Bi, Hongliang Yan, Junbo Zhang, Kaike Pan, Xiaodong Xu   +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?

The 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, Andrés Yagüe López, Benoit Côté, Maria K. Pető, Chiaki Kobayashi, Maria Lugaro   +5 more
doaj   +1 more source

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

The 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

Chemical Tracing and the Origin of Carbon in the Galactic Disk

Universe, 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]

, 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., de Graauw T., Feldman U., Fluks M. A., Grevesse N., J. Bernard‐Salas, J. R. Houck, Monk D. J., P. W. Morris, Pena M., S. Gutenkunst, S. R. Pottasch, Zijlstra A. A.   +12 more
core   +4 more sources