Goswami Principles and Perspectives in Cosmochemistry

Lecture Notes of the Kodai School on 'Synthesis of Elements in Stars' held at Kodaikanal Observatory, India, April 29 - May 13, 2008
1. Auflage 2010
ISBN: 978-3-642-10352-0
Verlag: Springer
Format: PDF
Kopierschutz: Wasserzeichen (»Systemvoraussetzungen)

E-Book, Englisch, 440 Seiten

A fundamental question in contemporary astrophysics is the origin of the elements. Cosmochemistry seeks to answer when, how and where the chemical elements arose. Quantitative answers to these fundamental questions require a multi-disciplinary approach involving stellar evolution, explosive nucleosynthesis and nuclear reactions in different astrophysical environments. There remain, however, many outstanding problems and cosmochemistry remains a fertile area of research. This book is among the first in recent times to put together the essentials of cosmochemistry, combining contributions from leading astrophysicists in the field. The chapters have been organized to provide a clear description of the fundamentals, an introduction to modern techniques such as computational modelling, and glimpses of outstanding issues.

Autoren/Hrsg.

Goswami, Aruna

Inhaltsverzeichnis

1;Principles and Perspectives in Cosmochemistry
;3
2;Preface;5
3;Contents;8
4;Part I Stellar Structure, Nucleosynthesis and Evolution of Low and Intermediate-mass Stars;15
4.1;Stellar Structure and Evolution: An Introduction;16
4.1.1;1 Introduction;16
4.1.2;2 The Hertzsprung–Russell Diagram;18
4.1.2.1;2.1 Cluster Diagrams;20
4.1.2.2;2.2 The Temperature–Luminosity Relation;24
4.1.2.3;2.3 The Mass–Luminosity and Mass-Radius Relations;24
4.1.3;3 Stellar Evolution – A Sneak Preview;24
4.1.4;4 Stellar Time Scales;28
4.1.4.1;4.1 Dynamical (Free-Fall) Time;28
4.1.4.2;4.2 Thermal (Kelvin) Time;29
4.1.4.3;4.3 Nuclear Time;30
4.1.4.4;4.4 Diffusion Time;30
4.1.4.5;4.5 Comparative Timescales;31
4.1.5;5 Equations of Stellar Structure;32
4.1.5.1;5.1 Mass Continuity;33
4.1.5.2;5.2 Hydrostatic Equilibrium;34
4.1.5.3;5.3 Virial Theorem;34
4.1.5.4;5.4 Energy Conservation;37
4.1.5.5;5.5 Energy Transport;38
4.1.5.6;5.6 The Equations of Stellar Structure;40
4.1.6;6 Equations of Stellar Evolution;42
4.1.6.1;6.1 Thermal Expansion (Contraction);42
4.1.6.2;6.2 Nucleosynthesis;42
4.1.6.3;6.3 Mixing;42
4.1.7;7 Equation of State;43
4.1.7.1;7.1 Gas Laws;43
4.1.7.2;7.2 Pressure;44
4.1.7.3;7.3 The Classical Ideal Gas;45
4.1.7.4;7.4 Mean Mass per Particle;45
4.1.7.5;7.5 Degenerate Electron Gas;46
4.1.7.6;7.6 Photons;47
4.1.7.7;7.7 Total Pressure;48
4.1.8;8 Stellar Opacity;49
4.1.8.1;8.1 Bound-Bound Absorption;50
4.1.8.2;8.2 Bound-Free Absorption;51
4.1.8.3;8.3 Free-Free Absorption;51
4.1.8.4;8.4 Electron Scattering;52
4.1.8.5;8.5 Total Absorption Coefficient;52
4.1.8.6;8.6 Electron Conduction;55
4.1.9;9 Thermonuclear Physics;55
4.1.9.1;9.1 Fusion;56
4.1.9.2;9.2 Reaction Rates;58
4.1.9.3;9.3 Reaction Networks;59
4.1.9.4;9.4 Nucleosynthesis of elements;64
4.1.9.5;9.5 Neutrinos;65
4.1.10;10 Approximate Solutions;66
4.1.10.1;10.1 Polytropic Gas Spheres;66
4.1.10.2;10.2 Clayton Models;67
4.1.10.3;10.3 Minimum Mass of a Star;70
4.1.10.4;10.4 Maximum Mass of a Star;71
4.1.11;11 Methods for Numerical Solution;72
4.1.11.1;11.1 Shooting Method;72
4.1.11.2;11.2 Difference Method;73
4.1.12;12 Stellar Evolution;75
4.1.12.1;12.1 Pre-Main-Sequence Evolution;75
4.1.12.2;12.2 The Zero-Age Main Sequence;76
4.1.12.3;12.3 Evolution of a 5M Star;79
4.1.12.4;12.4 Evolution at Other Masses;81
4.1.13;13 Stellar Remnants;81
4.1.13.1;13.1 White Dwarfs;81
4.1.13.2;13.2 Type II Supernovae;83
4.1.13.3;13.3 Neutron Stars;86
4.1.14;14 Horizontal Branch Stars;87
4.1.14.1;14.1 Horizontal Branch Stars in Clusters and the Field;88
4.1.14.2;14.2 Theoretical Models for Horizontal Branch Stars;88
4.1.14.3;14.3 Evolution of Horizontal Branch Stars;91
4.1.14.4;14.4 Extreme Horizontal Branch Stars;92
4.1.14.5;14.5 The Origin of EHB Stars;93
4.1.14.6;14.6 Extreme Horizontal Branch Stars in other Galaxies;97
4.1.15;15 Late Stages of Stellar Evolution: Hydrogen-Deficient Stars;97
4.1.15.1;15.1 Population I and Massive Hydrogen-Deficient Stars;98
4.1.15.2;15.2 Low-Mass Hydrogen-Deficient Supergiants;101
4.1.15.3;15.3 Hydrogen-Deficient Subdwarfs.;104
4.1.15.4;15.4 Central Stars of Planetary Nebulae;105
4.1.15.5;15.5 White Dwarfs;107
4.1.15.6;15.6 Post-AGB evolution;108
4.1.15.7;15.7 Double-Degenerate Mergers;111
4.1.16;16 Conclusion;112
4.1.17;References;112
4.2;Nucleosynthesis of Low and Intermediate-mass Stars;119
4.2.1;1 Introduction;119
4.2.2;2 Some preliminaries;121
4.2.3;3 Evolution and nucleosynthesis prior to the AGB;124
4.2.3.1;3.1 The Evolution of a 1M Star;125
4.2.3.2;3.2 The Evolution of a 5M Star;129
4.2.3.3;3.3 The First and Second Dredge-up;131
4.2.4;4 Evolution during the AGB;135
4.2.4.1;4.1 Carbon stars;143
4.2.4.2;4.2 Luminosity variability;143
4.2.4.3;4.3 Mass loss;144
4.2.5;5 Nucleosynthesis during the AGB;144
4.2.5.1;5.1 Nucleosynthesis in the hydrogen-burning shell;145
4.2.5.2;5.2 Nucleosynthesis during thermal pulses;146
4.2.5.3;5.3 Comparison with observations: Intershell abundances;150
4.2.5.4;5.4 Fluorine production in AGB stars;152
4.2.5.5;5.5 Extra-mixing process on the AGB;154
4.2.5.6;5.6 Hot bottom burning;155
4.2.5.7;5.7 The production of lithium by HBB;156
4.2.5.8;5.8 HBB and the C, N, and O isotopes;157
4.2.5.9;5.9 HBB and the Ne, Mg, and Al isotopes;160
4.2.5.10;5.10 Yields from AGB stars;160
4.2.6;6 The slow neutron-capture process;165
4.2.6.1;6.1 Neutron sources operating in AGB stars;166
4.2.6.2;6.2 Partial mixing and the formation of 13C pockets;167
4.2.6.3;6.3 The s-process in massive AGB stars;169
4.2.7;7 Concluding remarks;170
4.2.8;References;171
4.3;Spectral Classification: Old and Contemporary;177
4.3.1;1 Historical Account of Spectral Classification ;177
4.3.1.1;1.1 Luminosity Effects in Stellar Spectra;178
4.3.2;2 Classification Criteria for various spectral types ;180
4.3.2.1; O-type Stars ;180
4.3.2.2; B-type Stars ;180
4.3.2.3;A-type Stars ;182
4.3.2.4; F-type Stars ;183
4.3.2.5; G-type Stars ;183
4.3.2.6; K-type Stars ;183
4.3.2.7; Carbon Stars ;184
4.3.2.8; M-type Stars ;185
4.3.2.9; S-type Stars ;186
4.3.3;3 New Spectral types L and T ;186
4.3.3.1;3.1 The T dwarfs;186
4.3.4;4 Modification of MK system ;187
4.3.5;5 Contemporary methods of spectral classification ;189
4.3.6;References;191
5;Part II Massive Stars, Core Collapse, Explosive Nucleosynthesis;193
5.1;Weak Interaction Rates for Stellar Evolution, Supernovaeand r-Process Nucleosynthesis;194
5.1.1;1 Introduction;194
5.1.2;2 Some Nuclear Physics Basics;195
5.1.2.1;2.1 Shell Model;195
5.1.2.2;2.2 -decay;196
5.1.3;3 Overview of Core Collapse Supernovae;197
5.1.4;4 Weak Interaction Processes in Supernova Evolution;200
5.1.4.1;4.1 At the Pre-SN Stage;200
5.1.4.2;4.2 At the Collapse Stage;200
5.1.4.3;4.3 Mechanisms of Unblocking;201
5.1.4.4;4.4 At the late time neutrino heating stage;202
5.1.5;5 Nuclear Models for Calculation of the Weak Interaction Rates;203
5.1.5.1;5.1 Systematics with simple shell structure;203
5.1.5.2;5.2 Statistical models for strength;203
5.1.5.3;5.3 Microscopic Models;205
5.1.5.4;5.4 Calculations with Improved Rates;206
5.1.6;6 Weak Interaction Processes During pp-Chain and Solar Neutrino Problem;209
5.1.6.1;6.1 Neutrino Oscillation;211
5.1.7;7 -decay Rates for r-Process Nucleosynthesis;213
5.1.7.1;7.1 s-process and r-process;214
5.1.7.2;7.2 Possible r-process site;215
5.1.7.3;7.3 Models for calculation of -decay rates for r-process nuclei;216
5.1.8;8 Concluding Remarks;217
5.1.9;References;218
5.2;Massive stars as thermonuclear reactors and their explosions following core collapse;220
5.2.1;1 Introduction;220
5.2.2;2 Stars and their thermonuclear reactions;223
5.2.2.1;2.1 Why do the stars burn slowly: a look at Gamow peaks;224
5.2.2.2;2.2 Gamow peak and the astrophysical S-factor;226
5.2.3;3 Hydrogen burning: the pp chain;232
5.2.3.1;3.1 Cross-section for deuterium formation;233
5.2.3.2;3.2 Deuterium burning;237
5.2.3.3;3.3 3He burning;240
5.2.3.4;3.4 Reactions involving 7Be;240
5.2.3.4.1;Electron capture process;240
5.2.3.4.2;Capture reaction leading to 8B;242
5.2.4;4 The CNO cycle and hot CNO;243
5.2.4.1;4.1 Hot CNO and rp-process;246
5.2.5;5 Helium burning and the triple- reaction;247
5.2.6;6 Survival of 12C in red giant stars and 12C(, )16O reaction;251
5.2.7;7 Advanced stages of thermonuclear burning;253
5.2.7.1;7.1 Carbon burning;254
5.2.7.2;7.2 Neon burning;257
5.2.7.3;7.3 Oxygen burning;258
5.2.7.4;7.4 Silicon burning;258
5.2.8;8 Core collapse SNe: electron capture and neutrinos;260
5.2.8.1;8.1 Electron capture on nuclei and protons: a core thermometer;261
5.2.8.2;8.2 Number of neutrinos emitted and predictions of detections;264
5.2.9;9 Detected neutrinos from SN 1987A and future neutrino watch;266
5.2.10;10 What X-ray spectroscopy reveals about nucleosynthesis in SNe and SNRs;267
5.2.10.1;10.1 Supernova Remnant Cassiopeia A;268
5.2.10.1.1;X-ray grating spectra of Cassiopeia A and SN 1987A;273
5.2.10.2;10.2 Live radioactive decays in Cas A, SN 1987A;276
5.2.10.3;10.3 Other X-ray supernovae;278
5.2.11;References;281
5.3;The Evolution of Massive Stars and the Concomitant Non-explosive and Explosive Nucleosynthesis;287
5.3.1;1 Introduction;287
5.3.2;2 Some generalities about the evolution of massive stars;288
5.3.3;3 Non-explosive stellar evolution and concomitant nucleosynthesis;291
5.3.3.1;3.1 Hydrogen burning;291
5.3.3.2;3.2 Helium burning and the s-process;292
5.3.3.3;3.3 Carbon burning;293
5.3.3.4;3.4 Neon, oxygen, and silicon burning;295
5.3.4;4 The explosive fate of massive stars;299
5.3.5;5 Nucleosynthesis associated with CCSN events;303
5.3.6;6 The synthesis of the nuclides heavier than iron: generalities;304
5.3.6.1;6.1 The bulk Solar System composition;305
5.3.6.2;6.2 The s-, r- and p-nuclides in the Solar System;306
5.3.6.3;6.3 Isotopic anomalies in the solar composition;311
5.3.6.4;6.4 Evolution of the r-nuclide content of the Galaxy;313
5.3.6.5;6.5 Can the available isotopic data tell something about the prevalence of the s- or of the r-process at early galactic times?;315
5.3.6.6;6.6 Actinides in the Solar System, in the Local Interstellar Medium, and in stars;317
5.3.6.7;6.7 The r-nuclide content of Galactic Cosmic Rays;319
5.3.7;7 The astrophysics of the r-process: parametrized site-free scenarios;320
5.3.7.1;7.1 Canonical and `multi-event r-process (MER)' high-temperature models;320
5.3.7.2;7.2 Dynamical high-temperature r-process approaches (DYR);324
5.3.7.3;7.3 A high-density r-process scenario (HIDER);326
5.3.8;8 The neutrino-driven DCCSNe: a high-temperaturesite for the r-process?;327
5.3.9;9 Compact objects: a site for the high-densityr-process scenario?;331
5.3.10;10 Some brief comments on the modelling of the evolution of the r-nuclide content of the Galaxyand on nucleo-cosmochronology;333
5.3.11;11 The p-process: Some generalities;335
5.3.11.1;11.1 The p-process in SN IIe;337
5.3.11.2;11.2 The p-process in SNIa;341
5.3.11.3;11.3 The p-process in sub-Chandrasekhar white dwarf explosions;342
5.3.11.4;11.4 Some comments on the p-process isotopic anomaliesand chronometry;345
5.3.12;12 Summary and prospects;346
5.3.13;References;351
6;Part III Cosmochemistry and Solar System Abundances;354
6.1;Cosmochemistry;355
6.1.1;1 Introduction;355
6.1.2;2 Computational Methods;355
6.1.3;3 Cosmochemical Behaviour of the Elements;359
6.1.3.1;3.1 Refractory Elements;359
6.1.3.2;3.2 Major elements;368
6.1.3.3;3.3 Moderately Volatile Elements;369
6.1.3.4;3.4 Highly Volatile Elements;374
6.1.3.5;3.5 Atmophile Elements;376
6.1.4;4 Summary;384
6.1.5;References;385
6.2;Solar System Abundances of the Elements;386
6.2.1;1 Motivations to Study Solar System Elemental Abundances;386
6.2.2;2 Meteorites as Abundance Standards for Non-Volatile Solar System Matter;387
6.2.2.1;2.1 Composition of CI chondrites;391
6.2.3;3 Photospheric abundances;392
6.2.4;4 Recommended Present-Day Solar Abundances;402
6.2.4.1;4.1 Cosmochemical and Astronomical Abundance Scale Conversion;402
6.2.4.2;4.2 Comparison of Photospheric and Meteoritic Abundances;404
6.2.4.3;4.3 Combined Solar Abundances from CI Chondritesand Photospheric Data;405
6.2.4.4;4.4 Mass Fractions X, Y, and Z in Present-Day Solar Material;408
6.2.5;5 Solar System Abundances 4.56 Gyr Ago;411
6.2.6;6 Abundance of the Nuclides;411
6.2.7;References;422
6.3;Cosmochemistry: A Perspective;425