Accretion Power in Astrophysics
Third Edition
Juhan Prank
Department of Physics and Astronomy, Louisiana State University, Baton Rouge
Andrew King
Astronomy Group, University of Leicester
Derek Raine
Astronomy Group, University of Leicester
CAMBRIDGE
UNIVERSITY PRESS
Contents
Preface to the first edition
Preface to the second edition
Preface to the third edition
page ix
xi
xiii
1 ACCRETION AS A SOURCE OF ENERGY
1.1
1.2
1.3
1.4
1
Introduction
The Eddington limit
The emitted spectrum
Accretion theory and observation
1
2
5
6
2 GAS DYNAMICS
2.1
2.2
2.3
2.4
2.5
Introduction
The equations of gas dynamics
Steady adiabatic flows; isothermal
Sound waves
Steady, spherically symmetric accretion
8
flows
3 PLASMA CONCEPTS
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
Introduction
Charge neutrality, plasma oscillations and the Debye length
Collisions
Thermal plasmas: relaxation time and mean free path
The stopping of fast particles by a plasma
Transport phenomena: viscosity
The effect of strong magnetic fields
Shock waves in plasmas
4 ACCRETION IN BINARY SYSTEMS
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
Introduction
Interacting binary systems
Roche lobe overflow
Roche geometry and binary evolution
Disc formation
Viscous torques
The magnitude of viscosity
Beyond the a-prescript ion
Accretion in close binaries: other possibilities
8
8
11
12
14
23
23
23
26
30
32
34
37
41
48
48
48
49
54
58
63
69
71
73
vi Contents
5 ACCRETION DISCS
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
5.11
5.12
5.13
Introduction
Radial disc structure
Steady thin discs
The local structure of thin discs
The emitted spectrum
The structure of steady a-discs (the 'standard model')
Steady discs: confrontation with observation
Time dependence and stability
Dwarf novae
Irradiated discs
Tides, resonances and superhumps
Discs axound young stars
Spiral shocks
6 ACCRETION ON TO A COMPACT OBJECT
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
Introduction
Boundary layers
Accretion on to magnetized neutron stars and white dwarfs
Accretion columns: the white dwarf case
Accretion column structure for neutron stars
X-ray bursters
Black holes
Accreting binary systems with compact components
7 ACTIVE GALACTIC NUCLEI
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
Observations
The distances of active galaxies
The sizes of active galactic nuclei
The mass of the central source
Models of active galactic nuclei
The gas supply
Black holes
Accretion efficiency
8 ACCRETION DISCS IN ACTIVE GALACTIC NUCLEI
8.1
8.2
8.3
8.4
8.5
8.6
8.7
The nature of the problem
Radio, millimetre and infrared emission
Optical, UV and X-ray emission
The broad and narrow, permitted and forbidden
The narrow line region
The broad line region
The stability of AGN discs
9 ACCRETION POWER IN ACTIVE GALACTIC NUCLEI
9.1
9.2
9.3
9.4
9.5
Introduction •»'
Extended radio sources
Compact radio sources
The nuclear continuum
Applications to discs
80
80
80
84
88
90
93
98
110
121
129
139
148
150
152
152
152
158
174
191
202
207
209
213
213
220
223
225
228
230
234
238
244
244
246
247
250
252
255
265
267
267
267
272
278
281
Contents
9.6
9.7
9.8
9.9
vii
Magnetic
Newtonian electrodynamic discs
The Blandford-Znajek model
Circuit analysis of black hole power
fields
285
287
289
292
10 THICK DISCS
10.1
10.2
10.3
10.4
10.5
10.6
10.7
296
Introduction
Equilibrium
The limiting luminosity
Newtonian vorticity-free torus
Thick accretion discs
Dynamical stability
Astrophysical implications
296
298
303
306
309
314
316
figures
11 ACCRETION FLOWS
ill
11.2
11.3
11.4
11.5
11.6
11.7
11.8
Introduction
The equations
Vertically integrated equations - slim discs
A unified description of steady accretion
Stability
Optically thin ADAFs — similarity solutions
Astrophysical applications
Caveats and alternatives
11.9 Epilogue
•
Appendix Radiation processes
Problems
Bibliography
.
Index
319
flows
319
320
323
325
331
333
334
337
342
345
350
366
380