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Evolution of Stars and Stellar Populations

Maurizio Salaris, Santi Cassisi

ISBN: 978-0-470-03345-6 May 2006 386 Pages


Evolution of Stars and Stellar Populations is a comprehensive presentation of the theory of stellar evolution and its application to the study of stellar populations in galaxies. Taking a unique approach to the subject, this self-contained text introduces first the theory of stellar evolution in a clear and accessible manner, with particular emphasis placed on explaining the evolution with time of observable stellar properties, such as luminosities and surface chemical abundances. This is followed by a detailed presentation and discussion of a broad range of related techniques, that are widely applied by researchers in the field to investigate the formation and evolution of galaxies.

This book will be invaluable for undergraduates and graduate students in astronomy and astrophysics, and will also be of interest to researchers working in the field of Galactic, extragalactic astronomy and cosmology.

  • comprehensive presentation of stellar evolution theory
  • introduces the concept of stellar population and describes "stellar population synthesis" methods to study ages and star formation histories of star clusters and galaxies
  • presents stellar evolution as a tool for investigating the evolution of galaxies and of the universe in general

1. Stars and the Universe.

1.1 Setting the stage.

1.2 Cosmic kinematics.

1.2.1 Cosmological redshifts and distances.

1.3 Cosmic dynamics.

1.3.1 Histories of R(t).

1.4 Particle- and nucleosynthesis.

1.5 CMB fluctuations and structure formation.

1.6 Cosmological parameters.

1.7 The inflationary paradigm.

1.8 The role of stellar evolution.

2. Equation of State of the Stellar Matter.

2.1 Physical conditions of the stellar matter.

2.1.1 Fully ionized perfect gas.

2.1.2 Electron degeneracy.

2.1.3 Ionization.

2.1.4 Additional effects.

3. Equations of Stellar Structure.

3.1 Basic assumptions.

3.1.1 Continuity of mass.

3.1.2 Hydrostatic equilibrium.

3.1.3 Conservation of energy.

3.1.4 Energy transport.

3.1.5 The opacity of stellar matter.

3.1.6 Energy generation coefficient.

3.1.7 Evolution of chemical element abundances.

3.1.8 Virial theorem.

3.1.9 Virial theorem and electron degeneracy.

3.2 Method of solution of the stellar structure equations.

3.2.1 Sensitivity of the solution to the boundary conditions.

3.2.2 More complicated cases.

3.3 Non-standard physical processes.

3.3.1 Atomic diffusion and radiative levitation.

3.3.2 Rotation and rotational mixings.

4. Star Formation and Early Evolution.

4.1 Overall picture of stellar evolution.

4.2 Star formation.

4.3 Evolution along the Hayashi track.

4.3.1 Basic properties of homogeneous, fully convective stars.

4.3.2 Evolution until hydrogen burning ignition.

5. The Hydrogen Burning Phase.

5.1 Overview.

5.2 The nuclear reactions.

5.2.1 The p-p chain.

5.2.2 The CNO cycle.

5.2.3 The secondary elements: The case of 2H and 3He.

5.3 The central H-burning phase in low main sequence (LMS) stars.

5.3.1 The Sun.

5.4 The central H-burning phase in upper main sequence (UMS) stars.

5.5 The dependence of MS tracks on chemical composition and convection efficiency.

5.6 Very low-mass stars.

5.7 The mass-luminosity relation.

5.8 The Schönberg-Chandrasekhar limit.

5.9 Post-MS evolution.

5.9.1 Intermediate-mass and massive stars.

5.9.2 Low-mass stars.

5.9.3 The helium flash.

5.10 Dependence of the main RGB features on physical and chemical parameters.

5.10.1 The location of the RGB in the H-R diagram.

5.10.2 The RGB bump luminosity.

5.10.3 The luminosity of the tip of the RGB.

5.11 Evolutionary properties of very metal-poor stars.

6. The Helium Burning Phase.

6.1 Introduction.

6.2 The nuclear reactions.

6.3 The zero age horizontal branch (ZAHB).

6.3.1 The dependence of the ZAHB on various physical parameters.

6.4 The core He-burning phase in low-mass stars.

6.4.1 Mixing processes.

6.5 The central He-burning phase in more massive stars.

6.5.1 The dependence of the blue loop on various physical parameters.

6.6 Pulsational properties of core He-burning stars.

6.6.1 The RR Lyrae variables.

6.6.2 The classical Cepheid variables.

7. The Advanced Evolutionary Phases.

7.1 Introduction.

7.2 The asymptotic giant branch (AGB).

7.2.1 The thermally pulsing phase.

7.2.2 On the production of s-elements.

7.2.3 The termination of the AGB evolutionary phase.

7.3 The Chandrasekhar limit and the evolution of stars with large CO cores.

7.4 Carbon-oxygen white dwarfs.

7.4.1 Crystallization.

7.4.2 The envelope.

7.4.3 Detailed WD cooling laws.

7.4.4 WDs with other chemical stratifications.

7.5 The advanced evolutionary stages of massive stars.

7.5.1 The carbon-burning stage.

7.5.2 The neon-burning stage.

7.5.3 The oxygen-burning stage.

7.5.4 The silicon-burning stage.

7.5.5 The collapse of the core and the final explosion.

7.6 Type Ia supernovae.

7.6.1 The Type Ia supernova progenitors.

7.6.2 The explosion mechanisms.

7.6.3 The light curves of Type Ia supernovae and their use as distance indicators.

7.7 Neutron stars.

7.8 Black holes.

8. From Theory to Observations.

8.1 Spectroscopic notation of the stellar chemical composition.

8.2 From stellar models to observed spectra and magnitudes.

8.2.1 Theoretical versus empirical spectra.

8.3 The effect of interstellar extinction.

8.4 K-correction for high-redshift objects.

8.5 Some general comments about colour-magnitude diagrams (CMDs).

9. Simple Stellar Populations.

9.1 Theoretical isochrones.

9.2 Old simple stellar populations (SSPs).

9.2.1 Properties of isochrones for old ages.

9.2.2 Age estimates.

9.2.3 Metallicity and reddening estimates.

9.2.4 Determination of the initial helium abundance.

9.2.5 Determination of the initial lithium abundance.

9.2.6 Distance determination techniques.

9.2.7 Luminosity functions and estimates of the IMF.

9.3 Young simple stellar populations.

9.3.1 Age estimates.

9.3.2 Metallicity and reddening estimates.

9.3.3 Distance determination techniques.

10. Composite Stellar Populations.

10.1 Definition and problems.

10.2 Determination of the star formation history (SFH).

10.3 Distance indicators.

10.3.1 The planetary nebula luminosity function (PNLF).

11. Unresolved Stellar Populations.

11.1 Simple stellar populations.

11.1.1 Integrated colours.

11.1.2 Absorption-feature indices.

11.2 Composite stellar populations.

11.3 Distance to unresolved stellar populations.

Appendix I: Constants.

Appendix II: Selected Web Sites.



"…ideal as a course resource. A must have…essential." (CHOICE, July 2006)

"…will serve generations of students to come as an authoritative reference which details how stars and stellar populations come to develop (and then evolve) over long blocks of time." (The Electric Review, March/April 2006)

  • Introduces the theory of stellar evolution alongside its applications to stellar populations.
  • Comprehensive presentation of stellar evolution theory with full explanations of the photometric and chemical properties of stars
  • Introduces the concept of stellar population from an observational perspective
  • Presents a comprehensive analysis of the physics necessary to understand how stars work and how they evolve.
  • Presents stellar evolution as a tool to investigate the evolution of galaxies and of the universe in general
  • Supplementary website with stellar evolution tracks and programmes to compute synthetic CMD’s integrated magnitudes and colours