|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'504'585
Articles rated: 2609
24 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
CNO and F abundances in the barium star HD 123396 | | Alan Alves-Brito
; Amanda Karakas
; David Yong
; Jorge Meléndez
; Sergio Vásquez
; | | Date: |
18 Jul 2011 | | Abstract: | [Abridged] Barium stars are moderately rare chemically peculiar objects which
are believed to be the result of the pollution of an otherwise normal star by
material from an evolved companion on the asymptotic giant branch (AGB). We aim
to derive carbon, nitrogen, oxygen, and fluorine abundances for the first time
from infrared spectra of the barium red giant star HD 123396 to quantitatively
test AGB nucleosynthesis models for producing barium stars via mass accretion.
High-resolution and high S/N infrared spectra were obtained using the Phoenix
spectrograph mounted at the Gemini South telescope. The abundances were
obtained through spectrum synthesis of individual atomic and molecular lines,
using the MOOG stellar line analysis program together with Kurucz’s stellar
atmosphere models. The analysis was classical, using 1D stellar models and
spectral synthesis under the assumption of local thermodynamic equilibrium. We
confirm that HD 123396 is a metal-deficient barium star ([Fe/H] = -1.05), with
A(C) = 7.88, A(N) = 6.65, A(O) = 7.93, and A(Na) = 5.28 in a logarithmic scale
where A(H) = 12, leading to [(C+N)/Fe] ~ 0.5. The A(CNO) group as well as the
A(Na) abundances are in excellent agreement with those previously derived for
this star using high resolution optical data. We also found A(F) = 4.16, which
implies [F/O] = 0.39, a value that is substantially higher than the F
abundances measured in globular clusters of a similar metallicity, noting that
there are no F measurements in field stars of comparable metallicity. The
observed abundance pattern of the light elements (CNO, F and Na) we recover
here as well as the heavy elements (s-process) studied by Allen & Barbuy (2006)
suggest that the surface composition of HD 123396 is well fitted by the
predicted abundance pattern of a 1.5Msun AGB model star with Z = 0.001. | | Source: | arXiv, 1107.3461 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER