scholarly journals Evolution and Nucleosynthesis in Extremely Metal-Poor, Asymptotic Giant Branch Stars

2009 ◽  
Vol 26 (3) ◽  
pp. 145-152 ◽  
Author(s):  
Nobuyuki Iwamoto
Keyword(s):  
Mass Loss ◽  
Surface Composition ◽  
Mass Range ◽  
Big Bang ◽  
Asymptotic Giant Branch ◽  
Light Nuclei ◽  
Efficient Production ◽  
Asymptotic Giant Branch Stars ◽  
Secondary Star ◽  
Low Mass

AbstractWe evolve extremely metal-poor ([Fe/H]≃–3), thermally pulsing Asymptotic Giant Branch (AGB) models with the mass range of 1–8 M⊙. The chemical yields ejected from the models are obtained by considering mass loss. We find that the 1- and 2-M⊙ AGB models are not affected by hot bottom burning (HBB). Nevertheless, they produce large amount of 7Li in an H-flash event. The occurrence of this event is associated with the ingestion of protons from the overlying H-rich envelope into the He convective shell driven by thermal pulse. The resulting 7Li abundances in the ejecta are higher than the primordial one predicted in Big-Bang nucleosynthesis. The efficient production of 7Li by the operation of HBB is also confirmed in the models of 4–8 M⊙. If these AGB stars have a low-mass companion, it is probable that mass loss from the primary AGB star brings the materials enriched in 7Li into the secondary star. This makes the surface composition of the secondary Li-rich. The formation of Li-rich stars, however, is strongly dependent on the mass loss history and binary separation. The nucleosynthesis for the other light nuclei is also calculated up to the end of the AGB phase. We find that the abundance patterns of the metal-poor stars CS 29528–041 and CS 29497–030 are well reproduced by yields from our AGB models.

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

2014 ◽  
Vol 790 (1) ◽  
pp. 22 ◽  
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 ◽  
Low Metallicity ◽  
Low Mass ◽  
Giant Branch Stars

scholarly journals Effects of Convective Overshooting, Mass Loss (and Chemical Composition) across the HR Diagram

1986 ◽  
Vol 116 ◽  
pp. 317-338
Author(s):  
C. Chiosi
Keyword(s):  
Mass Loss ◽  
Reaction Rate ◽  
Mass Range ◽  
Asymptotic Giant Branch ◽  
Stellar Structure ◽  
Asymptotic Giant Branch Stars ◽  
The Novel ◽  
Pressure Scale ◽  
Red Giant ◽  
Giant Branch Stars

The far reaching consequences of convective overshooting during the core H and He-burning phases of stars in the mass range 1.3 M⊙ to 100 M⊙ are discussed. In addition to this, the effects of mass loss in luminous stars of all spectral types, and in the red giant and asymptotic giant branch stars are briefly outlined. Furthermore, the effects of the novel 12C(α γ)16O reaction rate are also illustrated. The main purpose of this review resides however in lending convincing support to the idea that convective cores of real stars are greater than commonly supposed in classic models. To this aim, several observational embarrassments that could not be explained by classic models are reanalyzed in the light of the new ones. Since a much better agreement between theory and observations is now possible, we are inclined to conclude that convective overshooting may be of paramount importance in stellar structure theories and that convective cores in real stars ought to be larger by approximately one pressure scale height than predicted by classic models.

scholarly journals Mass loss and yield uncertainty in low-mass asymptotic giant branch stars

2007 ◽  
Vol 375 (4) ◽  
pp. 1280-1290 ◽  
Author(s):  
Richard J. Stancliffe ◽  
C. Simon Jeffery
Keyword(s):  
Mass Loss ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Low Mass ◽  
Yield Uncertainty ◽  
Giant Branch Stars

scholarly journals Asteroseismology of luminous red giants with Kepler. II. Dependence of mass loss on pulsations and radiation

2020 ◽  
Author(s):  
Jie Yu ◽  
Saskia Hekker ◽  
Timothy R Bedding ◽  
Dennis Stello ◽  
Daniel Huber ◽  
...  
Keyword(s):  
Mass Loss ◽  
Mass Loss Rate ◽  
Asymptotic Giant Branch ◽  
Red Giants ◽  
Asymptotic Giant Branch Stars ◽  
Chemical Enrichment ◽  
Dust Mass ◽  
Red Giant ◽  
The Masses ◽  
Loss Rates

Abstract Mass loss by red giants is an important process to understand the final stages of stellar evolution and the chemical enrichment of the interstellar medium. Mass-loss rates are thought to be controlled by pulsation-enhanced dust-driven outflows. Here we investigate the relationships between mass loss, pulsations, and radiation, using 3213 luminous Kepler red giants and 135000 ASAS–SN semiregulars and Miras. Mass-loss rates are traced by infrared colours using 2MASS and WISE and by observed-to-model WISE fluxes, and are also estimated using dust mass-loss rates from literature assuming a typical gas-to-dust mass ratio of 400. To specify the pulsations, we extract the period and height of the highest peak in the power spectrum of oscillation. Absolute magnitudes are obtained from the 2MASS Ks band and the Gaia DR2 parallaxes. Our results follow. (i) Substantial mass loss sets in at pulsation periods above ∼60 and ∼100 days, corresponding to Asymptotic-Giant-Branch stars at the base of the period-luminosity sequences C′ and C. (ii) The mass-loss rate starts to rapidly increase in semiregulars for which the luminosity is just above the red-giant-branch tip and gradually plateaus to a level similar to that of Miras. (iii) The mass-loss rates in Miras do not depend on luminosity, consistent with pulsation-enhanced dust-driven winds. (iv) The accumulated mass loss on the Red Giant Branch consistent with asteroseismic predictions reduces the masses of red-clump stars by 6.3%, less than the typical uncertainty on their asteroseismic masses. Thus mass loss is currently not a limitation of stellar age estimates for galactic archaeology studies.

Evolution and Nucleosynthesis in Low‐Mass Asymptotic Giant Branch Stars. I. Formation of Population I Carbon Stars

1997 ◽  
Vol 478 (1) ◽  
pp. 332-339 ◽  
Author(s):  
Oscar Straniero ◽  
Alessandro Chieffi ◽  
Marco Limongi ◽  
Maurizio Busso ◽  
Roberto Gallino ◽  
...  
Keyword(s):  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Carbon Stars ◽  
Low Mass ◽  
Giant Branch Stars

scholarly journals THE MASS-LOSS RETURN FROM EVOLVED STARS TO THE LARGE MAGELLANIC CLOUD. II. DUST PROPERTIES FOR OXYGEN-RICH ASYMPTOTIC GIANT BRANCH STARS

2010 ◽  
Vol 716 (1) ◽  
pp. 878-890 ◽  
Author(s):  
Benjamin A. Sargent ◽  
S. Srinivasan ◽  
M. Meixner ◽  
F. Kemper ◽  
A. G. G. M. Tielens ◽  
...  
Keyword(s):  
Mass Loss ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Evolved Stars ◽  
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

Flash‐Driven Convective Mixing in Low‐Mass, Metal‐deficient Asymptotic Giant Branch Stars: A New Paradigm for Lithium Enrichment and a Possibles‐Process

2004 ◽  
Vol 602 (1) ◽  
pp. 377-387 ◽  
Author(s):  
Nobuyuki Iwamoto ◽  
Toshitaka Kajino ◽  
Grant J. Mathews ◽  
Masayuki Y. Fujimoto ◽  
Wako Aoki
Keyword(s):  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
New Paradigm ◽  
Convective Mixing ◽  
Low Mass ◽  
Giant Branch Stars ◽  
Lithium Enrichment

scholarly journals EVOLUTION, NUCLEOSYNTHESIS, AND YIELDS OF LOW-MASS ASYMPTOTIC GIANT BRANCH STARS AT DIFFERENT METALLICITIES

2009 ◽  
Vol 696 (1) ◽  
pp. 797-820 ◽  
Author(s):  
S. Cristallo ◽  
O. Straniero ◽  
R. Gallino ◽  
L. Piersanti ◽  
I. Domínguez ◽  
...  
Keyword(s):  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Low Mass ◽  
Giant Branch Stars
Sign in / Sign up

Export Citation Format

Share Document