Describing interstellar matter in our galaxy in all of its various forms, this book also considers the physical and chemical processes that are occurring within this matter. The first seven chapters present the various components making up the interstellar matter and detail the ways that we are able to study them. The following seven chapters are devoted to the physical, chemical and dynamical processes that control the behaviour of interstellar matter. These include the instabilities and cloud collapse processes that lead to the formation of stars. The last chapter summarizes the transformations that can occur between the different phases of the interstellar medium. Emphasizing methods over results, The Interstellar Medium is written for graduate students, for young astronomers, and also for any researchers who have developed an interest in the interstellar medium.
Author(s): James Lequeux E. Falgarone C. Ryter
Edition: 1
Year: 2004
Language: English
Pages: 444
Contents......Page 9
1 Our Galaxy, Host of the Interstellar Medium......Page 15
1.1 Our Galaxy: Orders of Magnitude......Page 16
1.2.1 Generalities......Page 19
1.2.2 The Disk Populations......Page 20
1.2.3 The Bulge and the Halo......Page 22
1.3 Distribution of Interstellar Matter......Page 23
2.1.1 Extragalactic Radiation......Page 27
2.1.2 Galactic Radiation......Page 29
2.2 The InterstellarMagnetic Fields......Page 34
2.2.1 Magnetic Field Measurements Using the Zeeman Effect......Page 35
2.2.2 Measurement of the Magnetic Fields Using Faraday Rotation......Page 36
2.2.3 Estimate of the Magnetic Fields from the Galactic Synchrotron Radiation......Page 37
2.2.4 Estimate of the Direction of the Magnetic Fields from the Linear Polarization of Light......Page 38
2.2.5 Results......Page 39
3.1.1 Demonstration......Page 41
3.1.2 The Rayleigh–Jeans Approximation: Radioastronomy Notations......Page 44
3.1.3 Excitation Temperature......Page 46
3.2.1 General Relations......Page 47
3.2.3 The Coupling of Excitation and Transfer; the LVG Approximation......Page 49
3.3 The General Case; Masers......Page 53
4.1.1 The 21-cm Line of Atomic Hydrogen......Page 59
4.1.2 Fine-Structure Lines in the Far-Infrared......Page 65
4.1.3 Interstellar Absorption Lines......Page 69
4.2.1 Introduction......Page 77
4.2.2 Electronic Transitions......Page 80
4.2.3 Vibrational Transitions......Page 85
4.2.4 Rotational Transitions......Page 87
4.2.5 The Diffuse Interstellar Bands......Page 97
5.1.1 Theory of Photoionization: the Strömgren Sphere......Page 100
5.1.2 Continuous Emission......Page 104
5.1.3 The Recombination Lines......Page 109
5.1.4 The Radio Recombination Lines......Page 114
5.1.5 The Forbidden Lines......Page 118
5.1.6 Abundance Determinations in H II Regions......Page 121
5.2 The Diffuse Ionized Gas......Page 123
5.3 The Hot Gas......Page 125
5.3.1 Collisional Ionization by Electrons at High Temperatures......Page 126
5.3.2 The Emission of X-Ray Lines......Page 128
5.3.4 Results......Page 129
5.4 The X-Ray Absorption......Page 130
6.1 Cosmic Rays......Page 132
6.1.2 Solar Cosmic Rays and Solar Modulation......Page 133
6.1.3 Galactic Cosmic Rays......Page 135
6.1.4 Very High-Energy Cosmic Rays......Page 141
6.1.5 Cosmic Electrons......Page 142
6.1.6 Confinement of Cosmic Rays in the Galaxy......Page 143
6.2.1 Gamma-Ray Production by Nuclear Interactions......Page 146
6.2.2 Gamma-Ray Production by Bremsstrahlung......Page 149
6.3 The Mass of the Interstellar Medium......Page 150
6.3.1 The Use of Gamma-Ray Observations to Determine the Mass of the Interstellar Medium in the Galaxy......Page 151
6.3.2 Use of the Virial Mass of Molecular Clouds......Page 154
6.3.3 A Comparison Between W[sub(CO)] and Extinction......Page 155
6.3.4 A Comparison Between W[sub(CO)] and Millimetre/Submillimetre Dust Emission......Page 156
6.3.5 X-Ray and Mid-Infrared Absorptions......Page 157
6.4 The Gamma-Ray Lines......Page 158
7 Interstellar Dust......Page 162
7.1.1 General Ideas......Page 163
7.1.2 Extinction and Dust Models......Page 168
7.1.3 X-Ray Scattering by Dust......Page 171
7.2.1 Grains in Thermal Equilibrium......Page 172
7.2.2 Small Grains out of Thermal Equilibrium......Page 175
7.2.3 The Aromatic Emission Bands in the Mid-Infrared......Page 180
7.2.4 The Very Small Grains.......Page 185
7.3 Global Dust Models......Page 186
7.4 Infrared Absorptions and Ice Mantles......Page 187
7.5 The Infrared Fluorescence......Page 190
8 Heating and Cooling of the Interstellar Gas......Page 191
8.1.1 Generalities, Thermalization Time......Page 192
8.1.2 Heating by Low-Energy Cosmic Rays......Page 195
8.1.3 Photoelectric Heating from Grains......Page 199
8.1.4 Photoelectric Heating by the Photoionization of Atoms and Molecules......Page 203
8.1.5 X-Ray Heating......Page 204
8.1.7 Heating by Grain-Gas Thermal Exchange......Page 206
8.1.8 Hydrodynamic and Magnetohydrodynamic Heating......Page 208
8.2.1 Fine-Structure Line Cooling......Page 209
8.2.2 Cooling by the Collisional Excitation of Permitted Lines......Page 211
8.2.3 Cooling by Electron–Ion Recombination......Page 214
8.3.1 The Atomic Medium......Page 215
8.3.3 H II Regions......Page 219
8.3.4 Molecular Clouds......Page 220
9.1 Gas-Phase Chemistry......Page 221
9.1.1 Ion–Molecule Reactions......Page 222
9.1.2 Radiative Association......Page 223
9.1.3 Dissociative Recombination......Page 224
9.1.4 Neutral–Neutral Reactions......Page 225
9.1.5 Photodissociation and Photoionization......Page 226
9.2 Chemistry on Dust Grains......Page 227
9.2.1 H[sub(2)] Formation on Grains......Page 228
9.2.2 Formation of Other Molecules on Grains......Page 230
9.3 Equilibrium Chemistry and Chemical Kinetics......Page 231
9.4.1 Chemistry in the Diffuse Interstellar Medium......Page 233
9.4.2 Chemistry in Dense Molecular Clouds......Page 235
10.1 General Presentation......Page 239
10.2.1 The Penetration of Far-UV Radiation and Photodissociation......Page 241
10.2.3 Heating Processes......Page 242
10.2.4 Cooling Processes......Page 244
10.3 Stationary Models......Page 245
10.4 Out of Equilibrium Models......Page 252
11.1.1 A Single-Fluid Medium......Page 253
11.1.2 A Multi-Fluid Medium......Page 255
11.2 Different Types of Shocks......Page 256
11.2.1 Shocks with no Magnetic Field......Page 257
11.2.2 Shocks in a Magnetized Medium......Page 261
11.2.3 Multi-Fluid Shocks in a Weakly Ionized Gas......Page 262
11.3 Non-Stationary Shocks......Page 264
11.4 Physico-Chemistry in Shocks......Page 266
11.5 Radiation and the Diagnosis of Shocks......Page 269
11.6 Instabilities in Shocks......Page 271
12.1 Supernova Remnants......Page 274
12.1.1 The Free Expansion Phase......Page 275
12.1.2 The Adiabatic Phase......Page 276
12.1.3 The Isothermal, or Radiative, Expansion Phase......Page 278
12.1.4 The Evolution of Plerions......Page 279
12.1.5 The Expansion of Supernova Remnants in an Inhomogeneous Medium......Page 280
12.1.6 Non-Thermal Radiation of Supernova Remnants......Page 281
12.2 Bubbles......Page 283
12.3 The Dynamics of H II Regions......Page 285
12.3.1 The Ionization Front......Page 286
12.3.2 The Shock......Page 289
12.3.3 Neutral Globules in a H II Region......Page 290
12.3.4 The Evolution of H II Regions......Page 294
12.4 The Acceleration of Cosmic Rays......Page 295
12.4.1 Propagation of Charged Particles in a Magnetic Field......Page 296
12.4.2 Diffusion of Charged Particles in a Disordered Medium......Page 299
12.4.3 Energy Losses......Page 302
12.4.4 The Acceleration of Charged Particles......Page 303
13.1 Velocity Structure and Fragmentation......Page 312
13.2.1 The Birth of Turbulence......Page 315
13.2.2 The Developed Kolmogorov Turbulence......Page 316
13.2.3 Turbulent Viscosity and Pressure......Page 318
13.2.4 Intermittency......Page 319
13.3 Turbulence in the Interstellar Medium......Page 320
13.4.1 Turbulent Transport and Interstellar Chemistry......Page 323
13.4.2 Intermittency of Turbulence Dissipation as a Gas Heating Source......Page 324
14.1.1 A Simple Form of the Virial Theorem with No Magnetic Field nor External Pressure......Page 331
14.1.2 The Jeans Length and Jeans Mass......Page 333
14.1.3 The General Form of the Virial Theorem......Page 336
14.1.4 The Stability of the Virial Equilibrium......Page 337
14.1.5 The Density Distribution in a Spherical Cloud at Equilibrium......Page 341
14.1.6 Stability and Instabilities in the Presence of a Magnetic Field......Page 342
14.1.7 The Coupling of the Gas and Magnetic Fields: Ambipolar Diffusion......Page 345
14.2.1 The Free-Fall Time......Page 350
14.2.2 Collapse Configurations......Page 351
14.2.3 The Role of Rotation......Page 353
14.2.4 The Role of Magnetic Fields......Page 355
14.3 The End of Collapse: Star Formation......Page 357
14.4.1 Determinations of the Initial Mass Function, and Related Problems......Page 358
14.4.2 The Origin of the Initial Mass Function......Page 360
15 Changes of State and Transformations......Page 362
15.1.1 Ionized Gas and Exchanges with the Neutral Gas......Page 363
15.1.2 Atomic Gas–Molecular Gas Exchanges......Page 364
15.2 Hot Gas and the Galactic Fountain......Page 369
15.3 Gas–Dust Exchange......Page 372
15.4 Evolution of Interstellar Dust......Page 374
15.4.1 Dust in Circumstellar Envelopes and Planetary Nebulae......Page 375
15.4.2 Dust in the Interstellar Medium......Page 376
15.4.3 Dust Around Protostars and in the Solar System......Page 377
A Designation of the Most Used Symbols......Page 379
B Principal Physical Constants......Page 382
C Journal Titles Abbreviations......Page 385
References......Page 386
A......Page 400
C......Page 401
E......Page 402
H......Page 403
M......Page 404
P......Page 405
S......Page 406
Z......Page 407
Color Plates......Page 408
