Physics - Stellar Atmospheres

Physics topics

Home

Stellar Atmospheres

Celestial Mechanics

Classical Mechanics

Geometric Optics

Electricity and Magnetism

Thermodynamics

Physical Optics

Max Fairbairn's Planetary Photometry

Integrals and Differential Equations

Quadric Surfaces

Stellar Atmospheres (last updated: 2022 August 11)

Chapter 1. Definitions of and Relations between Quantities used in Radiation Theory

1.1 Introduction

1.2 Radiant Flux or Radiant Power

1.3 Variation with Frequency or Wavelength

1.4 Radiant Intensity

1.5 "Per Unit"

1.6 Relation between Flux and Intensity

1.7 Absolute Magnitude

1.8 Normal Flux Density

1.9 Apparent Magnitude

1.10 Irradiance

1.11 Exitance

1.12 Radiance

1.13 Lambertian Surface

1.14 Relations between Flux, Intensity, Exitance, Irradiance

1.15 A = πB

1.16 Radiation Density

1.17 Radiation Density and Irradiance

1.18 Radiation Pressure

Chapter 2. Blackbody Radiation

2.1 Introduction

2.2 Absorptance, and the Definition of a Black Body

2.3 Radiation within a Cavity Enclosure

2.4 Kirchhoff's Law

2.5 An Aperture as a Black Body

2.6 Planck's Equation

2.7 Wien's Law

2.8 Stefan's Law

2.9 A Thermodynamical Argument

2.10 Dimensionless Forms of Planck's Equation

2.11 Derivation of Wien's and Stefan's Laws

Chapter 3. The Exponential Integral Function

Chapter 4. Flux, Specific Intensity and other Astrophysical Terms

4.1 Introduction

4.2 Luminosity

4.3 Specific Intensity

4.4 Flux

4.5 Mean Specific Intensity

4.6 Radiation Pressure

4.7 Other Integrals

4.8 Emission Coefficient

Chapter 5. Absorption, Scattering, Extinction and the Equation of Transfer

5.1 Introduction

5.2 Absorption

5.3 Scattering, Extinction and Opacity

5.4 Optical Depth

5.5 The Equation of Transfer

5.6 The Source Function

5.7 A Series of Problems

5.8 Source Function in Scattering and Absorbing Atmospheres

5.9 More on the Equation of Transfer

Chapter 6. Limb Darkening

6.1 Introduction. The Empirical Limb-darkening

6.2 Simple Models of the Atmosphere to Explain Limb Darkening

Chapter 7. Atomic Spectroscopy

7.1 Introduction

7.2 A Very Brief History of Spectroscopy

7.3 The Hydrogen Spectrum

7.4 The Bohr Model of the Hydrogen Atom

7.5 One-dimensional Waves in a Stretched String

7.6 Vibrations of a Uniform Sphere

7.7 The Wave Nature of the Electron

7.8 Schrödinger's Equation

7.9 Solution of Schrödinger's Time-independent equation for the Hydrogen Atom

7.10 Operators, Eigenfunctions and Eigenvalues

7.11 Spin

7.12 Electron Configurations

7.13 LS-coupling

7.14 States, Levels, Terms, Polyads, etc.

7.15 Components, Lines, Mulitplets, etc.

7.16 Return to the Hydrogen Atom

7.17 How to Recognize LS-coupling

7.18 Hyperfine Structure

7.19 Isotope Effects

7.20 Orbiting and Spinning Charges

7.21 Zeeman Effect

7.22 Paschen-Back Effect

7.23 Zeeman Effect with Nuclear Spin

7.24 Selection Rules

7.25 Some Forbidden Lines Worth Knowing

7.26 Stark Effect

Chapter 8. Boltzmann's and Saha's Equations

8.1 Introduction

8.2 Stirling's Approximation. Lagrangian Multipliers.

8.3 Some Thermodynamics and Statistical Mechanics

8.4 Boltzmann's Equation

8.5 Some Comments on Partition Functions

8.6 Saha's Equation

8.7 The Negative Hydrogen Ion

8.8 Autoionization and Dielectronic Recombination

8.9 Molecular Equilibrium

8.10 Thermodynamic Equilibrium

Chapter 9. Oscillator Strengths and Related Topics

9.1 Introduction. Radiance and Equivalent Width

9.2 Oscillator Strength

9.3 Einstein A Coefficient

9.4 Einstein B Coefficient

9.5 Line Strength

9.6 LS-Coupling

9.7 Atomic Hydrogen

9.8 Zeeman Components

9.9 Summary of Relations Between f, A and S.

Chapter 10. Line Profiles

10.1 Introduction

10.2 Natural Broadening (Radiation Damping)

10.3 Thermal Broadening

10.4 Microturbulence

10.5 Combination of Profiles

10.6 Pressure Broadening

10.7 Rotational Broadening

10.8 Instrumental Broadening

10.9 Other Line-broadening Mechanisms

Appendix A Convolution of Gaussian and Lorentzian Functions

Appendix B Radiation Damping as Functions of Angular Frequency, Frequency and Wavelength

Appendix C Optical Thinness, Homogeneity and Thermodynamic Equilibrium

Chapter 11. Curve of Growth

11.1 Introduction

11.2 A Review of Some Terms

11.3 Theory of the Curve of Growth

11.4 Curve of Growth for Gaussian Profiles

11.5 Curve of Growth for Lorentzian Profiles

11.6 Curve of Growth for Voigt Profiles

11.7 Observational Curve of Growth

11.8 Interpreting an Optically Thick Profile

Appendix A Evaluation of the Voigt Curve of Growth Integral