scholarly journals Relations between the galactic evolution and the stellar evolution

1984 ◽  
Vol 105 ◽  
pp. 541-548 ◽  
Author(s):  
Jean Audouze
Keyword(s):  
Chemical Evolution ◽  
Stellar Evolution ◽  
Galactic Evolution ◽  
Evolution Of Galaxies ◽  
The Impact

The question which has been raised in many chapters of this book is about the existence of constraints on stellar evolution coming from related topics like cosmology or in the case of the present chapter the chemical evolution of the galaxies. As it will be seen in this contribution it seems wiser to consider that chemical evolution of galaxies is indeed related to the problem of stellar evolution discussed here but is not going to provide as many constraints on it as one would expect. The purpose of this presentation is therefore to outline the principal relations between these two fields and to discuss the impact of some recent works on them.

scholarly journals Massive Stars and Galactic Evolution

1991 ◽  
Vol 143 ◽  
pp. 625-638
Author(s):  
Francesca Matteucci
Keyword(s):  
Chemical Evolution ◽  
White Dwarfs ◽  
Massive Stars ◽  
Theoretical Models ◽  
Galactic Evolution ◽  
Point Of View ◽  
Galactic Chemical Evolution ◽  
Evolution Of Galaxies

The evolution and nucleosynthesis in massive stars are briefly reviewed, and compared with the information derived from SN1987A in LMC. Most of the theoretical models agree with the measured abundances and they can be used in models of galactic evolution.Models of chemical evolution of galaxies are presented and the role of massive stars in their evolution is discussed.Finally, the role of Wolf-Rayet stars in galactic evolution is studied, particularly from the point of view of their final fate. It is shown that, if Wolf-Rayet were the progenitors of type Ib supernovae, the Galactic chemical evolution would not change substantially with respect to the case of white dwarfs being the progenitors of type Ib supernovae. However, the predicted frequency of type Ib supernovae in the Wolf- Rayet case would be far too low in comparison with observational estimates.

Stellar Evolution

1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild
Keyword(s):  
Solar System ◽  
Stellar Evolution ◽  
Space Craft ◽  
New Techniques ◽  
Substantial Body ◽  
Individual Stars ◽  
The Past ◽  
Evolution Of Galaxies ◽  
History Of ◽  
Fast Flow

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.

scholarly journals The Impact of Nuclear Physics Uncertainties on Galactic Chemical Evolution Predictions

2020 ◽  
Vol 1668 (1) ◽  
pp. 012008
Author(s):  
Benoit Côté ◽  
Pavel Denissenkov ◽  
Falk Herwig ◽  
Chris L. Fryer ◽  
Krzysztof Belczynski ◽  
...  
Keyword(s):  
Chemical Evolution ◽  
Nuclear Physics ◽  
Galactic Chemical Evolution ◽  
The Impact

scholarly journals Formation of GW190521 from stellar evolution: the impact of the hydrogen-rich envelope, dredge-up and 12C(α, γ)16O rate on the pair-instability black hole mass gap

2020 ◽  
Author(s):  
Guglielmo Costa ◽  
Alessandro Bressan ◽  
Michela Mapelli ◽  
Paola Marigo ◽  
Giuliano Iorio ◽  
...  
Keyword(s):  
Stellar Evolution ◽  
Reaction Rate ◽  
Primary Component ◽  
Mass Reduction ◽  
Black Hole Mass ◽  
Core Mass ◽  
The Core ◽  
Mass Gap ◽  
M Stars ◽  
The Impact

Abstract Pair-instability (PI) is expected to open a gap in the mass spectrum of black holes (BHs) between ≈40 − 65 M⊙ and ≈120 M⊙. The existence of the mass gap is currently being challenged by the detection of GW190521, with a primary component mass of $85^{+21}_{-14}$ M⊙. Here, we investigate the main uncertainties on the PI mass gap: the 12C(α, γ)16O reaction rate and the H-rich envelope collapse. With the standard 12C(α, γ)16O rate, the lower edge of the mass gap can be 70 M⊙ if we allow for the collapse of the residual H-rich envelope at metallicity Z ≤ 0.0003. Adopting the uncertainties given by the starlib database, for models computed with the 12C(α, γ)16O rate −1 σ, we find that the PI mass gap ranges between ≈80 M⊙ and ≈150 M⊙. Stars with MZAMS > 110 M⊙ may experience a deep dredge-up episode during the core helium-burning phase, that extracts matter from the core enriching the envelope. As a consequence of the He-core mass reduction, a star with MZAMS = 160 M⊙ may avoid the PI and produce a BH of 150 M⊙. In the −2 σ case, the PI mass gap ranges from 92 M⊙ to 110 M⊙. Finally, in models computed with 12C(α, γ)16O −3 σ, the mass gap is completely removed by the dredge-up effect. The onset of this dredge-up is particularly sensitive to the assumed model for convection and mixing. The combined effect of H-rich envelope collapse and low 12C(α, γ)16O rate can lead to the formation of BHs with masses consistent with the primary component of GW190521.

scholarly journals ENHANCED MASS LOSS RATES IN RED SUPERGIANTS AND THEIR IMPACT ON THE CIRCUMSTELLAR MEDIUM

2019 ◽  
Vol 55 (2) ◽  
pp. 161-175
Author(s):  
L. Hernández-Cervantes ◽  
B. Pérez-Rendón ◽  
A. Santillán ◽  
G. García-Segura ◽  
C. Rodríguez-Ibarra
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Gas Dynamics ◽  
Numerical Experiments ◽  
Evolutionary Models ◽  
Solar Composition ◽  
Red Supergiants ◽  
The Impact ◽  
Circumstellar Medium ◽  
Loss Rates

In this work, we present models of massive stars between 15 and 23 M⊙ , with enhanced mass loss rates during the red supergiant phase. Our aim is to explore the impact of extreme red supergiant mass-loss on stellar evolution and on their circumstellar medium. We computed a set of numerical experiments, on the evolution of single stars with initial masses of 15, 18, 20 and, 23 M⊙ , and solar composition (Z = 0.014), using the numerical stellar code BEC. From these evolutionary models, we obtained time-dependent stellar wind parameters, that were used explicitly as inner boundary conditions in the hydrodynamical code ZEUS-3D, which simulates the gas dynamics in the circumstellar medium (CSM), thus coupling the stellar evolution to the dynamics of the CSM. We found that stars with extreme mass loss in the RSG phase behave as a larger mass stars.

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