Structure Formation in Astrophysics (Cambridge Contemporary Astrophysics)

Half-title......Page 3
Title......Page 5
Copyright......Page 6
Contents......Page 7
Contributors......Page 9
Preface......Page 11
Part I Physical Processes and Numerical Methods Common to Structure Formations in Astrophysics......Page 13
1 The physics of turbulence......Page 15
1.1 General comments on turbulence......Page 16
1.2 What is the source of turbulence?......Page 17
1.3 What are the main statistical features of turbulence?......Page 19
1.4.1.1 The concept of turbulent viscosity......Page 23
1.4.1.3 One-equation model: the k-model......Page 24
1.4.1.4 Two-equation model: the (k–ε) model......Page 25
1.4.2.1 The general context......Page 26
1.4.2.2 The Smagorinsky model......Page 28
1.4.2.3 The shear-improved Smagorinsky model......Page 29
References......Page 31
2 The numerical simulation of turbulence......Page 32
2.1 Fundamentals......Page 33
2.2 Supersonic turbulence......Page 36
2.3 Self-gravitating turbulence......Page 39
2.4 Magnetohydrodynamic turbulence......Page 42
2.5 Perspectives......Page 45
References......Page 47
3.1 Introduction......Page 49
3.2.1 Introduction......Page 50
3.2.3 Discretization......Page 52
3.2.5 Riemann solvers......Page 54
3.2.6 Constrained transport......Page 55
3.2.8.1 Linear wave convergence......Page 56
3.2.8.2 Propagation of circularly polarized Alfvén wave......Page 57
3.2.8.4 Shocktube rotated to the grid......Page 58
3.2.8.5 MHD blast wave......Page 59
3.3 Radiation-hydrodynamic algorithms: the Orion code......Page 60
3.3.1 Limiting regimes of radiation hydrodynamics......Page 63
3.3.2 The equations of radiation hydrodynamics......Page 64
3.3.3 The relative importance of higher-order terms......Page 71
3.3.3.1 Comparison to lower-order equations......Page 72
3.3.3.2 Comparison to comoving frame formulations......Page 73
3.3.4 Radiation hydrodynamics in the static diffusion limit......Page 74
3.3.5 Advantages of the method......Page 76
3.3.6.1 Radiating blast wave......Page 77
3.3.6.2 Radiation pressure tube......Page 83
3.3.6.3 Radiation-inhibited Bondi accretion......Page 85
3.4 Adaptive mesh refinement......Page 88
3.5 Conclusions and future directions......Page 92
Acknowledgements......Page 93
References......Page 94
4.1 Introduction......Page 96
4.2.1 Protostellar objects......Page 99
4.2.3 Black holes......Page 100
4.3 Theory of disk winds......Page 101
4.3.1.1 Conservation of mass and magnetic flux......Page 102
4.3.1.2 Conservation of angular momentum......Page 103
4.3.1.3 Conservation of energy......Page 104
4.3.3 Jet power and universality......Page 105
4.3.4 Jet collimation......Page 106
4.4 Gravitational collapse, disks and the origin of outflows......Page 107
4.5 Feedback from collimated protostellar jets?......Page 110
4.6 Relativistic jets: theory......Page 113
4.7 SRMHD and GRMHD simulations......Page 114
4.8 Non-relativistic versus relativistic MHD jets......Page 117
References......Page 118
5.1 Numerical methods in AFD......Page 122
5.2 Timescales in AFD......Page 124
5.3 Numerical methods: a unification approach......Page 129
5.3.1 Example......Page 131
5.4 Converting time-explicit into implicit solution methods......Page 132
5.7 Why Boltzmann Solvers?......Page 134
5.8 Equations and implementation: Proteus......Page 135
5.9.1 1D: resistively damped linear Alfvén wave......Page 136
5.9.2 1D: linear Alfvén waves in weakly ionized plasmas......Page 137
5.9.3 2D: current sheet......Page 139
5.9.4 2D: advection of a field loop......Page 140
References......Page 141
Part II: Structure and Star Formation in the Primordial Universe......Page 143
6.1 Introduction......Page 145
6.2.1 Dark matter......Page 148
6.2.2.1 Type Ia SNe......Page 150
6.3 First light and cosmic reionization......Page 154
6.4.1 Disk galaxies......Page 157
6.4.2 Early-type galaxies......Page 158
6.4.3 Feedback......Page 159
6.4.4 Downsizing......Page 160
6.5 Where next?......Page 165
6.5.2 21-cm facilities......Page 166
6.5.3 Theory......Page 167
References......Page 168
7.2 Fast versus slow structure formation......Page 171
7.3 The importance of H2 cooling in early galaxy formation......Page 174
7.4 Simulating a 108M galaxy one star at a time......Page 175
7.5 A minimum mass for galaxies?......Page 178
7.6 The cosmic star formation rate......Page 179
7.7 The role of diffuse gas accretion......Page 181
7.8 The role of AGN feedback......Page 183
7.9 Star formation in quiescent disk galaxies......Page 185
7.10 Conclusions......Page 189
References......Page 190
8.1 Introduction......Page 192
8.1.2 What is the nature of the feedback exerted by the first stars on their surroundings?......Page 193
8.2.1.1 How did the first stars form?......Page 194
8.2.1.2 How massive were the first stars?......Page 195
8.2.1.3 Can a Pop III star ever reach this asymptotic mass limit?......Page 196
8.2.2 Second-generation stars......Page 197
8.3.1.2 Mass loss......Page 200
8.3.3 Very massive stars and pair instability supernovae......Page 202
8.3.5 The remnants of the first stars......Page 205
8.4.1.1 Photoionization/evaporation......Page 206
8.4.1.3 Photoheating filtering......Page 208
8.4.2 Chemical feedback......Page 209
8.4.3.1 Are metals in galaxies or in the IGM?......Page 210
References......Page 212
Part III Contemporary Star and Brown Dwarf Formation......Page 215
9.1 Introduction......Page 217
9.2 Large-scale interstellar medium......Page 218
9.3 Neutral interstellar medium......Page 221
9.3.1 Thermal balance and thermal instability......Page 222
9.3.2 Dynamical formation of cold atomic clouds......Page 223
9.3.3 Front stability and thermal fragmentation......Page 224
9.3.4 Colliding flows and thermally bistable turbulence......Page 225
9.3.5 Dense structure statistics in thermally bistable turbulent flows......Page 227
9.3.6 Influence of the magnetic field......Page 229
9.4.1 Context......Page 230
9.4.2 Numerical results......Page 231
9.4.3 Formation of molecular hydrogen......Page 233
9.4.4 Discussion and implications......Page 235
References......Page 237
10.2 Observations of clustered and distributed populations in molecular clouds......Page 240
10.2.1 Molecular cloud surveys......Page 241
10.2.2 A gallery of embedded clusters......Page 242
10.2.3 The distribution of protostars in embedded clusters......Page 243
10.2.4 The evolution of embedded clusters: an observational perspective......Page 245
10.3 Local theory of distributed and clustered star formation......Page 247
10.3.1 Ambipolar diffusion and distributed star formation......Page 248
10.3.2 Turbulence, gravity and cluster formation......Page 250
10.3.3 Cluster formation in protostellar turbulence......Page 252
10.4 Global theory of star formation in turbulent clouds......Page 254
10.4.1 Questions and difficulties......Page 255
10.4.2 A turbulent cascade origin of the scaling......Page 256
10.4.3 Interaction of turbulence and self-gravity......Page 258
10.4.4 Self-regulated star formation......Page 260
10.5 Concluding remarks......Page 261
References......Page 262
11.1 Introduction: dense cores and the origin of the IMF......Page 266
11.2 Link between the prestellar CMF and the IMF......Page 267
11.3 Core formation models versus observational constraints......Page 272
11.3.1 Theoretical description of cloud fragmentation models......Page 273
11.3.2.1 Core formation efficiency and spatial distribution from surveys......Page 279
11.3.2.2 Core lifetimes......Page 280
11.3.2.3 Magnetic field measurements......Page 281
11.3.2.4 Radial density structure......Page 283
11.3.2.5 Velocity structure......Page 284
11.4.1 Core collapse models: thermodynamics......Page 286
11.4.1.1 Dynamical roles of the first and second protostellar cores......Page 288
11.4.2.1 MHD modelling with resistivity......Page 290
11.5 Conclusions: proposed view for the star formation process......Page 294
References......Page 295
12.1 Introduction......Page 300
12.2.1 The model......Page 302
12.2.2.2 Core spatial and kinematic distributions......Page 303
12.2.2.3 The star formation rate......Page 305
12.2.3.1 Initial fragmentation......Page 306
12.2.3.2 Massive protostellar disks and companion formation......Page 308
12.3 The competitive accretion model......Page 309
12.3.1 Initial fragmentation......Page 310
12.3.2 Accretion in a cluster potential......Page 311
12.3.4 Limitations of competitive accretion......Page 312
12.3.5 Predictions......Page 313
12.3.6 Observational comparisons......Page 314
12.4.1 Radiation pressure......Page 315
12.4.2 Ionization......Page 317
12.5.1.1 Micro scales......Page 319
12.5.1.2 Meso scales......Page 320
12.5.1.3 Macro scales......Page 322
12.5.2.1 Cluster formation with feedback......Page 323
12.5.2.2 Fragmentation and feedback with magnetic fields......Page 324
References......Page 325
Part IV Protoplanetary Disks and Planet Formation......Page 333
13.1 Introduction......Page 335
13.2.1 Observational approaches......Page 336
13.2.3 Disks and planet formation: initial conditions and overall evolution......Page 337
13.2.4 Disks and planet formation: first stages......Page 339
13.2.5 Disks and planet formation: final stages......Page 340
13.3.1.1 T-Tauri stars......Page 342
13.3.1.2 Herbig Ae/Be stars and protostars......Page 345
13.3.2 X-rays and magnetic fields......Page 346
13.4.1 Introduction......Page 349
13.4.2 Accretion and outflow signatures in brown dwarfs......Page 350
13.4.3 Measuring the accretion rates......Page 352
13.4.4 Dependence of Macc on central mass......Page 353
13.4.5 Implications for brown dwarf formation......Page 355
13.4.6 Further formation constraints: recent and future observations......Page 356
References......Page 358
14.2 The birth and death of a protoplanetary disk......Page 362
14.3.1 Basic vertical structure......Page 366
14.3.2 2D and 3D radiative transfer models......Page 367
14.4.1 Instabilities and structure formation......Page 368
14.4.2 GI basics and transport......Page 370
14.4.3 Fragmentation of \'real\' disks......Page 372
14.4.4 Unified and hybrid theories......Page 374
14.5 Planet–disk interactions......Page 375
14.5.1 The disk response: spiral waves torques and orbital migration......Page 376
14.5.2 Type I migration......Page 377
14.5.3 Non-linearity, gap formation and type II migration......Page 380
Acknowledgements......Page 383
References......Page 384
15.2.1 General overview......Page 390
15.2.2.1 General features......Page 392
15.2.2.2 Planetary mass distribution......Page 393
15.2.2.3 Orbital characteristics......Page 394
15.2.2.4 Primary star properties......Page 395
15.2.3 Exoplanet characterization......Page 396
15.2.4 The future: A quest for terrestrial planets......Page 398
15.3.1 Introduction......Page 399
15.3.2 Planet formation by disk instability......Page 400
15.3.3 The core-accretion paradigm......Page 401
15.3.4 Refined core-accretion models......Page 403
15.3.5 Population synthesis......Page 404
15.3.5.1 Initial conditions and detection biases......Page 405
15.3.5.2 Results......Page 406
15.4.1 Introduction......Page 409
15.4.2.1 Observational constraints......Page 410
15.4.2.3 Summary on accretion effects......Page 412
15.4.3.1 Definitions......Page 413
15.4.3.3 Inner structure diagnostic......Page 414
15.5 Conclusions......Page 417
References......Page 418
16.2 Planetesimals......Page 422
16.2.1 Gas–grain coupling times......Page 423
16.2.2 First fractal growth phase......Page 424
16.2.3 From centimetre to decimetre......Page 425
16.2.4 Metre-size bodies and their problems......Page 426
16.2.5 Processing (pre-)planetesimals in the inner disk......Page 427
16.3 The compositions of giant planets: clues to the formation of planetary systems......Page 428
16.3.1 Jupiter and Saturn......Page 429
16.3.2 Uranus and Neptune......Page 431
16.3.3 Extrasolar planets......Page 432
16.3.4 Consequences for formation models......Page 434
References......Page 435
Part V Summary......Page 437
17.2 Planet formation......Page 439
17.3 Star formation......Page 441
17.4 Galaxy formation......Page 445
17.5 Similarities and dissimilarities......Page 447
References......Page 450
18 A final word......Page 453
18.1 Science and politics......Page 454
18.2 Occam\'s razor......Page 455