Laser chemistry: spectroscopy, dynamics and applications

Astrophysics......Page 4
Contents......Page 10
Preface......Page 16
Acknowledgments......Page 18
Introduction......Page 20
Appendix: dimensions, units and equations......Page 25
PART I THE SIGNAL OBSERVED......Page 32
1.1 The power of light - luminosity and spectral power......Page 34
1.2 Light through a surface - flux and flux density......Page 38
1.3 The brightness of light - intensity and specific intensity......Page 40
1.4 Light from all angles - energy density and mean intensity......Page 44
1.5 How light pushes - radiation pressure......Page 47
1.6.1 Apparent magnitude......Page 50
1.6.2 Absolute magnitude......Page 53
1.6.3 The colour index, bolometric correction, and HR diagram......Page 54
1.6.4 Magnitudes beyond stars......Page 55
Problems......Page 56
2.1 Spectral filters and the panchromatic universe......Page 60
2.2 Catching the signal - the telescope......Page 63
2.2.1 Collecting and focussing the signal......Page 65
2.2.2 Detecting the signal......Page 67
2.2.3 Field of view and pixel resolution......Page 68
2.2.4 Diffraction and diffraction-limited resolution......Page 69
2.3 The Corrupted signal - the atmosphere......Page 72
2.3.1 Atmospheric refraction......Page 73
2.3.2 Seeing......Page 74
2.3.3 Adaptive optics......Page 76
2.3.5 Atmospheric reddening......Page 79
2.4.1 Correcting the signal......Page 80
2.5 Analysing the signal......Page 81
2.6 Visualizing the signal......Page 83
Problems......Page 86
Appendix: refraction in the Earth\'s atmosphere......Page 89
PART II MATTER AND RADIATION ESSENTIALS......Page 94
3.1 The Big Bang......Page 96
3.2 Dark and light matter......Page 97
3.3.2 Stellar evolution and ISM enrichment......Page 101
3.3.3 Supernovae and explosive nucleosynthesis......Page 106
3.3.4 Abundances in the Milky Way, its star formation history and the IMF......Page 108
3.4 The gaseous universe......Page 113
3.4.1 Kinetic temperature and the Maxwell-Boltzmann velocity distribution......Page 115
3.4.2 The ideal gas......Page 119
3.4.3 The mean free path and collision rate......Page 120
3.4.4 Statistical equilibrium, thermodynamic equilibrium, and LTE......Page 124
3.4.5 Excitation and the Boltzmann Equation......Page 127
3.4.6 Ionization and the Saha Equation......Page 131
3.4.7 Probing the gas......Page 132
3.5 The dusty Universe......Page 135
3.5.1 Observational effects of dust......Page 136
3.5.2 Structure and composition of dust......Page 140
3.5.3 The origin of dust......Page 142
3.6.1 Cosmic ray composition......Page 143
3.6.2 The cosmic ray energy spectrum......Page 144
3.6.3 The origin of cosmic rays......Page 148
Problems......Page 149
Appendix: the electron/proton ratio in cosmic rays......Page 152
4.1 Black body radiation......Page 154
4.1.1 The brightness temperature......Page 158
4.1.2 The Rayleigh-Jeans Law and Wien\'s Law......Page 160
4.1.3 Wien\'s Displacement Law and stellar colour......Page 161
4.1.4 The Stefan-Boltzmann Law, stellar luminosity and the HR diagram......Page 163
4.2 Grey bodies and planetary temperatures......Page 165
4.2.1 The equilibrium temperature of a grey body......Page 167
4.2.2 Direct detection of extrasolar planets......Page 171
Problems......Page 174
4.A.1 The statistical weight......Page 177
4.A.2 The mean energy per state......Page 178
4.A.3 The specific energy density and specific intensity......Page 179
PART III THE SIGNAL PERTURBED......Page 182
5 The interaction of light with matter......Page 184
5.1 The photon redirected - scattering......Page 185
5.1.1 Elastic scattering......Page 188
5.1.2 Inelastic scattering......Page 196
5.2.1 Particle kinetic energy - heating......Page 199
5.2.2 Change of state - ionization and the Stro¨mgren sphere......Page 200
5.3 The wavefront redirected - refraction......Page 203
5.4.2 Dynamics of opacity – pulsation and stellar winds......Page 206
5.5 The opacity of dust - extinction......Page 213
Problems......Page 214
6.1 Types of energy transfer......Page 218
6.2 The equation of transfer......Page 220
6.3.1 Case A: no cloud......Page 222
6.3.3 Case C: emitting, but not absorbing cloud......Page 223
6.3.5 Case E: emitting and absorbing cloud......Page 224
6.3.6 Case F: emitting and absorbing cloud in LTE......Page 225
6.4.1 Implications for temperature......Page 226
6.4.2 Observability of emission and absorption lines......Page 227
6.4.3 Determining temperature and optical depth of HI clouds......Page 231
Problems......Page 235
7.1 Space and time......Page 238
7.2.1 The Doppler shift - deciphering dynamics......Page 241
7.2.2 The expansion redshift......Page 248
7.2.3 The gravitational redshift......Page 250
7.3.1 Geometry and mass of a gravitational lens......Page 251
7.3.2 Microlensing - MACHOs and planets......Page 256
7.3.3 Cosmological distances with gravitational lenses......Page 257
7.4 Time variability and source size......Page 258
Problems......Page 259
PART IV THE SIGNAL EMITTED......Page 264
8 Continuum emission......Page 266
8.1 Characteristics of continuum emission – thermal and non-thermal......Page 267
8.2.1 The thermal Bremsstrahlung spectrum......Page 268
8.2.2 Radio emission from HII and other ionized regions......Page 273
8.2.3 X-ray emission from hot diffuse gas......Page 276
8.3 Free–bound (recombination) emission......Page 282
8.4 Two-photon emission......Page 284
8.5 Synchrotron (and cyclotron) radiation......Page 286
8.5.1 Cyclotron radiation – planets to pulsars......Page 289
8.5.2 The synchrotron spectrum......Page 293
8.5.3 Determining synchrotron source properties......Page 299
8.5.4 Synchrotron sources - spurs, bubbles, jets, lobes and relics......Page 301
8.6 Inverse Compton radiation......Page 304
Problems......Page 307
9 Line emission......Page 310
9.1.1 Electronic transitions - optical and UV lines......Page 311
9.1.2 Rotational and vibrational transitions - molecules, IR and mm-wave spectra......Page 312
9.1.3 Nuclear transitions -g-rays and high energy events......Page 317
9.2 The line strengths, thermalization, and the critical gas density......Page 319
9.3 Line broadening......Page 321
9.3.1 Doppler broadening and temperature diagnostics......Page 322
9.3.2 Pressure broadening......Page 326
9.4 Probing physical conditions via electronic transitions......Page 327
9.4.1 Radio recombination lines......Page 328
9.4.2 Optical recombination lines......Page 333
9.4.3 The 21 cm line of hydrogen......Page 338
9.5.1 The CO molecule......Page 342
Problems......Page 344
PART V THE SIGNAL DECODED......Page 348
10.1.1 Isolating the signal......Page 350
10.1.2 Modelling the signal......Page 352
10.2 Case studies - the active, the young, and the old......Page 356
10.2.1 Case study 1: the Galactic Centre......Page 357
10.2.2 Case study 2: the Cygnus star forming complex......Page 360
10.2.3 Case study 3: the globular cluster, NGC 6397......Page 362
10.3 The messenger and the message......Page 366
Problems......Page 367
A.2 Binomial expansion......Page 370
A.5 Properties of the ellipse......Page 371
B.1 One-dimensional and two-dimensional angles......Page 374
B.2 Solid angle and the spherical coordinate system......Page 375
C.1 The hydrogen spectrum and principal quantum number......Page 378
C.2 Quantum numbers, degeneracy, and statistical weight......Page 383
C.3 Fine structure and the Zeeman effect......Page 384
C.4 The l 21 cm line of neutral hydrogen......Page 385
Appendix D: Scattering processes......Page 388
D.1.1 Scattering from free electrons – Thomson scattering......Page 389
D.1.2 Scattering from bound electrons I: the oscillator model......Page 390
D.1.3 Scattering from bound electrons II: quantum mechanics......Page 393
D.1.4 Scattering from bound electrons III: resonance scattering and the natural line shape......Page 394
D.1.5 Scattering from bound electrons IV: Rayleigh scattering......Page 397
D.2 Inelastic scattering – Compton scattering from free electrons......Page 398
D.3 Scattering by dust......Page 400
Appendix E: Plasmas, the plasma frequency, and plasma waves......Page 404
F.1 Kinematics of the Universe......Page 408
F.2 Dynamics of the Universe......Page 414
F.3 Kinematics, dynamics and high redshifts......Page 417
Appendix G: Tables and figures......Page 420
References......Page 432
Index......Page 438
Colour insert......Page 449