scholarly journals The Uncertainties in the22Ne+α‐Capture Reaction Rates and the Production of the Heavy Magnesium Isotopes in Asymptotic Giant Branch Stars of Intermediate Mass

2006 ◽  
Vol 643 (1) ◽  
pp. 471-483 ◽  
Author(s):  
A. I. Karakas ◽  
M. A. Lugaro ◽  
M. Wiescher ◽  
J. Gorres ◽  
C. Ugalde
Keyword(s):  
Reaction Rates ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Intermediate Mass ◽  
Magnesium Isotopes ◽  
Capture Reaction ◽  
Giant Branch Stars

scholarly journals Rubidium, zirconium, and lithium production in intermediate-mass asymptotic giant branch stars

2012 ◽  
Vol 540 ◽  
pp. A44 ◽  
Author(s):  
M. A. van Raai ◽  
M. Lugaro ◽  
A. I. Karakas ◽  
D. A. García-Hernández ◽  
D. Yong
Keyword(s):  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Intermediate Mass ◽  
Giant Branch Stars

scholarly journals EVOLUTION OF THERMALLY PULSING ASYMPTOTIC GIANT BRANCH STARS. V. CONSTRAINING THE MASS LOSS AND LIFETIMES OF INTERMEDIATE-MASS, LOW-METALLICITY AGB STARS

2016 ◽  
Vol 822 (2) ◽  
pp. 73 ◽  
Author(s):  
Philip Rosenfield ◽  
Paola Marigo ◽  
Léo Girardi ◽  
Julianne J. Dalcanton ◽  
Alessandro Bressan ◽  
...  
Keyword(s):  
Mass Loss ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Agb Stars ◽  
Intermediate Mass ◽  
Low Metallicity ◽  
Giant Branch Stars

scholarly journals The Chemical Evolution of Magnesium Isotopic Abundances in the Solar Neighbourhood

2003 ◽  
Vol 20 (4) ◽  
pp. 340-344 ◽  
Author(s):  
Y. Fenner ◽  
B. K. Gibson ◽  
H.-c. Lee ◽  
A. I. Karakas ◽  
J. C. Lattanzio ◽  
...  
Keyword(s):  
Chemical Evolution ◽  
Galactic Disk ◽  
Asymptotic Giant Branch ◽  
Solar Neighbourhood ◽  
Asymptotic Giant Branch Stars ◽  
Intermediate Mass ◽  
Intermediate Mass Stars ◽  
Isotopic Abundances ◽  
First Time ◽  
Giant Branch Stars

AbstractThe abundance of the neutron-rich magnesium isotopes observed in metal-poor stars is explained quantitatively with a chemical evolution model of the local Galaxy that considers — for the first time — the metallicity-dependent contribution from intermediate mass stars. Previous models that simulate the variation of Mg isotopic ratios with metallicity in the solar neighbourhood have attributed the production of 25Mg and 26Mg exclusively to hydrostatic burning in massive stars. These models match the data well for [Fe/H] > –1.0 but severely underestimate 25,26Mg/24Mg at lower metallicities. Earlier studies have noted that this discrepancy may indicate a significant role played by intermediate mass stars. Only recently have detailed calculations of intermediate mass stellar yields of 25Mg and 26Mg become available with which to test this hypothesis. In an extension of previous work, we present a model that successfully matches the Mg isotopic abundances in nearby Galactic disk stars through the incorporation of nucleosynthesis predictions of Mg isotopic production in asymptotic giant branch stars.

scholarly journals The Chemical Composition of Asymptotic Giant Branch Stars-the s-process

1991 ◽  
Vol 145 ◽  
pp. 299-316
Author(s):  
David L. Lambert
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
Neutron Source ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Agb Stars ◽  
Intermediate Mass ◽  
Low Mass ◽  
Giant Branch Stars

This review discusses the chemical composition of AGB stars in the light of predictions for intermediate-mass (3-8 M⊙, 22Ne(α,n) = the neutron source) and low-mass (< 3 M⊙, 13C(α,n) = the neutron source) stars. LM-AGB models can be constructed with envelopes having a composition quite similar to that of solar system material, the SiC grains recently discovered in meteorites, and real AGB stars in the sequence of spectral types M → S → C. Stellar counterparts of the IM-AGB models have yet to be discovered.

Mg and Al production in intermediate-mass asymptotic giant branch stars

2006 ◽  
Vol 50 (7-8) ◽  
pp. 500-503 ◽  
Author(s):  
A.I. Karakas ◽  
M. Lugaro ◽  
C. Ugalde ◽  
M. Wiescher ◽  
J. Görres
Keyword(s):  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Intermediate Mass ◽  
Giant Branch Stars

scholarly journals NUCLEOSYNTHESIS PREDICTIONS FOR INTERMEDIATE-MASS ASYMPTOTIC GIANT BRANCH STARS: COMPARISON TO OBSERVATIONS OF TYPE I PLANETARY NEBULAE

2008 ◽  
Vol 690 (2) ◽  
pp. 1130-1144 ◽  
Author(s):  
Amanda I. Karakas ◽  
Mark A. van Raai ◽  
Maria Lugaro ◽  
N. C. Sterling ◽  
Harriet L. Dinerstein
Keyword(s):  
Planetary Nebulae ◽  
Asymptotic Giant Branch ◽  
Type I ◽  
Asymptotic Giant Branch Stars ◽  
Intermediate Mass ◽  
Giant Branch Stars

scholarly journals On the fluorine nucleosynthesis in AGB stars in the light of the 19F(p,α)16O and 19F(α,p)22Ne reaction rate measured via THM

2019 ◽  
Vol 49 ◽  
pp. 1960011
Author(s):  
S. Palmerini ◽  
G. D’Agata ◽  
M. La Cognata ◽  
R. G. Pizzone ◽  
I. Indelicato ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reaction Rate ◽  
State Of The Art ◽  
Reaction Rates ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Agb Stars ◽  
Stellar Nucleosynthesis ◽  
Trojan Horse Method ◽  
Giant Branch Stars

In the last years the [Formula: see text]O and the [Formula: see text]F([Formula: see text],p)[Formula: see text]Ne reactions have been studied via the Trojan Horse Method in the energy range of interest for astrophysics. These are the first experimental data available for the main channels of [Formula: see text]F destruction that entirely cover the energy regions typical of the stellar H- and He- burning. In both cases the reaction rates are significantly larger than the previous estimations available in the literature. We present here a re-analysis of the fluorine nucleosynthesis in Asymptotic Giant Branch stars by employing in state-of-the-art models of stellar nucleosynthesis the THM reaction rates for [Formula: see text]F destruction.

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