This volume of original articles is the result of the work initiated in 2002 with the aim to extensively test, compare and optimize the numerical tools used to calculate stellar models and their oscillation frequencies.
This collection of papers provides a unique reference that covers 10 evolution codes and 9 oscillation codes. Most of these have been used to produce numerous results published over the years and have never before been fully described in literature. The comparisons that were carried out over a period of 4 years resulted in a comprehensive study that covered the numerical aspects of the different codes and the implementation of the physics they use, and have provided the basis for further development of the codes. The same work has also allowed for a detailed characterization of the precision and expected shortfalls of the models produced by these tools. Consequently, this volume is expected to be of great relevance for researchers and research students working on the modeling of stars and on the implementation of seismic test of stellar models. Moreover, it is expected to have a high impact on the analysis of the data acquired by (ongoing and future) ground-based instruments and space missions in helio- and astero-seismology.
Author(s): Mário Joao P. F. G. Monteiro
Edition: 1
Publisher: Springer
Year: 2008
Language: English
Pages: 267
Introduction......Page 8
ESTA organisation and tools......Page 9
Stellar internal structure and evolution codes......Page 10
TASK 1: basic stellar models......Page 11
TASK 2: oscillation frequencies......Page 12
Initial parameters......Page 13
Input physics......Page 14
Conclusion......Page 16
References......Page 17
Introduction......Page 20
Numerical scheme......Page 21
Equation of state......Page 23
Nuclear reactions......Page 24
Treatment of convection......Page 25
Further developments......Page 26
Acknowledgements......Page 27
Appendix 1: Treatment of diffusion and settling......Page 28
References......Page 29
Integration of the stellar structure......Page 32
Atomic diffusion......Page 34
The Standard Solar Model......Page 35
References......Page 36
Introduction......Page 38
Time steps......Page 39
Diffusion......Page 40
Running YREC......Page 41
Model grids......Page 42
Implemented equations......Page 43
Turbulent velocities......Page 44
Solar model with chi and gamma as independent variables......Page 45
SAL peak shift......Page 46
Acknowledgements......Page 47
References......Page 48
Introduction......Page 49
Nuclear networks......Page 50
Mass loss......Page 51
The diffusion equations......Page 52
Implicit finite elements method......Page 53
Application to the solar case......Page 54
Transport of angular momentum......Page 55
Magnetic fields and internal gravity waves......Page 56
Tayler-Spruit dynamo......Page 57
References......Page 58
Input physics......Page 61
Radiative diffusion......Page 62
Meridional circulation and rotation-induced mixing......Page 63
Evolution of angular momentum......Page 64
References......Page 65
The available packages......Page 67
The kinds of precision......Page 68
Choice of variables......Page 69
The grids......Page 70
Initial PMS model......Page 71
Evolution with diffusion......Page 72
Burgers's flow equations......Page 73
Calculation of mean charges......Page 74
Convection......Page 75
Calibration of the solar model......Page 76
Acknowledgements......Page 77
References......Page 78
Introduction......Page 80
Chemical evolution equations......Page 81
Atmospheric layers......Page 82
Solving for the structure given the abundances Xk,i......Page 83
Examples......Page 84
References......Page 87
Introduction......Page 88
Equation of state......Page 89
Nuclear reactions......Page 90
Convection......Page 91
Structure......Page 92
Interpolation in tables......Page 93
Calibration of solar models......Page 94
References......Page 95
Introduction......Page 97
Equation of state......Page 98
The macrophysics: convection models......Page 99
Overshooting......Page 100
The macrophysics: atmospheric structure and boundary conditions......Page 101
References......Page 102
Numerics......Page 103
Explicit time integration......Page 104
Mass loss......Page 105
Nuclear reactions......Page 106
Opacities......Page 107
Summary......Page 108
References......Page 109
Formulation of the adiabatic equations......Page 111
The Galerkin finite-element method......Page 112
Internal stability and accuracy......Page 113
Impact of stellar model mesh resolution......Page 114
References......Page 116
Equilibrium model......Page 117
Formulation of the equations......Page 118
Numerical scheme......Page 119
The shooting method......Page 120
Improving the frequency precision......Page 121
Computed quantities......Page 122
Acknowledgements......Page 123
References......Page 124
Basic equations for linear perturbations......Page 125
The equilibrium model......Page 126
At the atmosphere......Page 127
Numerical variables......Page 128
Accuracy of the results......Page 129
Acknowledgements......Page 130
References......Page 131
Adiabatic case......Page 132
Non-adiabatic resolution......Page 134
References......Page 136
Nonradial oscillations......Page 137
Outputs......Page 138
Additional tools for the initial model......Page 139
References......Page 141
Introduction......Page 143
Dimensionless variables......Page 144
Shooting method......Page 145
l=1 modes......Page 146
Numerical examples......Page 147
ModelJCA: improved hydrostatic equilibrium......Page 148
References......Page 149
Oscillation modes......Page 150
Nonradial oscillations......Page 151
Difference equations......Page 153
Applications......Page 154
References......Page 155
Introduction......Page 156
Oscillation frequencies of a pseudo-rotating model......Page 157
The boundary conditions......Page 158
filou inputs and outputs......Page 159
Numerical tests and results......Page 160
Results. The effect of shellular rotation on adiabatic oscillations......Page 161
References......Page 162
Methods of studying pulsating stars......Page 163
Stellar direct method. The LNAWENR numerical method......Page 164
Conclusions......Page 165
References......Page 166
Input physics and numerical aspects......Page 167
Initial parameters of the models......Page 168
ADIPLS oscillation frequencies......Page 169
References......Page 170
Introduction......Page 172
GRID A: evolution from fully convective spheres......Page 173
GRID B: evolution from a birthline......Page 174
Evolutionary tracks and stellar models......Page 175
References......Page 176
Input physics......Page 178
Evolutionary tracks......Page 179
Stellar models......Page 181
Seismic properties......Page 182
References......Page 183
Introduction......Page 185
Numerical tools......Page 186
Presentation of the comparisons and general results......Page 187
Low-mass models: Cases 1.1, 1.2 and 1.3......Page 190
Intermediate mass models: Cases 1.4 and 1.5......Page 192
High mass models: Cases 1.6 and 1.7......Page 193
Convection regions and ionisation zones......Page 194
Solar-like oscillations: Cases 1.1, 1.2 and 1.3......Page 197
Cases 1.4 and 1.5......Page 198
Cases 1.6 and 1.7......Page 199
Presentation of the comparisons and general results......Page 200
Internal structure......Page 202
Solar-type stars with convective cores: Cases 3.2 and 3.3......Page 203
Convection zones......Page 204
Helium surface abundance......Page 205
Summary and conclusions......Page 206
References......Page 210
Comparison between relevant physical quantities......Page 212
Comparison between the variables used in the frequency computations......Page 214
References......Page 215
Equation of State......Page 216
Opacities......Page 218
Effects on global stellar parameters......Page 219
Effects on the stellar structure......Page 221
Effects on the frequencies......Page 222
Atmosphere......Page 223
Numerical aspects......Page 224
Conclusions......Page 225
References......Page 226
Abstract......Page 227
Introduction......Page 228
The equilibrium models......Page 229
Oscillation codes and requirements......Page 230
Radial modes......Page 231
Non-radial modes with l=2......Page 233
Large separation of radial modes......Page 236
Non-radial modes with l=2......Page 237
Small separations delta02......Page 239
The influence of the gravitational constant G......Page 240
The choice of dependent variables and equations......Page 241
The choice of independent variable......Page 242
Conclusions......Page 243
References......Page 244
Introduction......Page 246
A study case......Page 247
The `data'......Page 248
`Modelling' the proxy star......Page 249
Frequency comparisons......Page 251
Comparison with CLES model: ESTA `calibration'......Page 252
Stellar structures......Page 253
Stellar structure......Page 254
Evolved stars......Page 255
References......Page 256
