1．Why Record Spectra of Astronomical Objects?

1.1 A Historical Introduction

1.2 What One Can Learn from Studying Spectra

2．The Nature of Spectra

2.1 Transitions

2.2 Absorption and Emission

2.3 Other Measures of Transition Probabilities

2.4 Stimulated Emission

2.5 Optical Depth

2.6 Critical Density

2.7 Wavelength or Frequency?

2.8 The Electromagnetic Spectrum

3．Atomic Hydrogen

3.1 Overview

3.2 The Schr？dinger Equation of Hydrogen-Like Atoms

3.3 Reduced Mass

3.4 Atomic Units

3.5 Wavefunctions for Hydrogen

3.6 Energy Levels and Quantum Numbers

3.7 H-Atom Discrete Spectra

3.8 H-Atom Spectra in Different Locations

3.8.1 Balmer series

3.8.2 Lyman series

3.8.3 Infrared lines

3.9 H-Atom Continuum Spectra

3.9.1 Processes

3.9.2 H-atom emission in H Ⅱ regions

3.10 Radio Recombination Lines

3.11 Radio Recombination Lines for Other Atoms

3.12 Angular Momentum Coupling in the Hydrogen Atom

3.13 The Fine Structure of Hydrogen

3.14 Hyperfine Structure in the H Atom

3.15 Allowed Transitions

3.16 Hydrogen in Nebulae

4．Complex Atoms

4.1 General Considerations

4.2 Central Field Model

4.3 Indistinguishable Particles

4.4 Electron Configurations

4.5 The Periodic Table

4.6 Ions

4.7 Angular Momentum in Complex Atoms

4.7.1 L-S or Russell-Saunders coupling

4.7.2 j-j coupling

4.7.3 Why two coupling schemes?

4.8 Spectroscopic Notation

4.9 Parity of the Wavefunction

4.10 Terms and Levels in Complex Atoms

5．Helium Spectra

5.1 He Ⅰand He Ⅱ Spectra

5.2 Selection Rules for Complex Atoms

5.3 Observing Forbidden Lines

5.4 Grotrian Diagrams

5.5 Potential Felt by Electrons in Complex Atoms

5.6 Emissions of Helium-Like Ions

6．Alkali Atoms

6.1 Sodium

6.2 Spin-Orbit Interactions

6.3 Fine Structure Transitions

6.4 Astronomical Sodium Spectra

6.5 Other Alkali Metal-Like Spectra

7．Spectra of Nebulae

7.1 Nebulium

7.2 The Bowen Mechanism

7.3 Two Valence Electrons

7.4 Autoionisation and Recombination

8．X-Ray Spectra

8.1 The Solar Corona…………？

8.2 Isotope Effects

9．Molecular Structure

9.1 The Born-Oppenheimer Approximation

9.2 Electronic Structure of Diatomics

9.2.1 Labelling of electronic states

9.2.2 Symmetry

9.2.3 State labels

9.3 Schr？dinger Equation

9.4 Fractionation

9.5 Vibration-Rotation Energy Levels

9.6 Temperature Effects

9.6.1 Rotational state populations

9.6.2 Vibrational state populations

9.6.3 Electronic state populations

10．Molecular Spectra

10.1 Selection Rules:Pure Rotational Transitions

10.1.1 Isotope effects

10.1.2 Rotational spectra of other molecules

10.1.3 Rotational spectra of molecular hydrogen

10.2 Vibrational Transitions

10.2.1 Structure of the spectrum

10.2.2 Isotope effects

10.2.3 Hydrogen molecule vibrational spectra

10.3 Electronic Transitions

10.3.1 Selection rules

10.3.2 Vibrational selection rules

10.3.3 Rotational selection rules

10.3.4 Transition frequencies

10.3.5 Astronomical spectra

10.4 Non-1Σ Electronic States

10.5 Maser Emissions

Solutions to Model Problems

Further Reading and Bibliography

Index