Book contents
- Frontmatter
- Contents
- Preface
- List of constants
- List of conversion factors
- 1 The galactic ecosystem
- 2 Gas cooling
- 3 Gas heating
- 4 Chemical processes
- 5 Interstellar dust
- 6 Interstellar polycyclic aromatic hydrocarbon molecules
- 7 HII regions
- 8 The phases of the ISM
- 9 Photodissociation regions
- 10 Molecular clouds
- 11 Interstellar shocks
- 12 Dynamics of the interstellar medium
- 13 The lifecycle of interstellar dust
- 14 List of symbols
- Index of compounds
- Alphabetic list of molecular species
- Index of molecules
- Index of objects
- Index
14 - List of symbols
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Preface
- List of constants
- List of conversion factors
- 1 The galactic ecosystem
- 2 Gas cooling
- 3 Gas heating
- 4 Chemical processes
- 5 Interstellar dust
- 6 Interstellar polycyclic aromatic hydrocarbon molecules
- 7 HII regions
- 8 The phases of the ISM
- 9 Photodissociation regions
- 10 Molecular clouds
- 11 Interstellar shocks
- 12 Dynamics of the interstellar medium
- 13 The lifecycle of interstellar dust
- 14 List of symbols
- Index of compounds
- Alphabetic list of molecular species
- Index of molecules
- Index of objects
- Index
Summary
Nomenclature in astronomy is often very confusing if not intentionally obfuscating. Every subfield arbitrarily introduces its own symbols and a book encompassing many different subfields has to dance a fine line between consistency with common usage in the literature and avoiding internal confusion. I have tried to avoid using the same symbols for more than one quantity as much as possible but did not quite succeed. This glossary provides a list of symbols that are used throughout the book, often with a reference to the equation where the symbol is first introduced or best defined. In those cases where a symbol is used in a different way than listed here – and this is not obvious from the context – I have tried to redefine the symbol consistently in the text.
Aij Einstein A coefficient (Eq. 2.17)
Aj The abundance of species j (Eq. 2.37)
Av The dust extinction at visual wavelength, in magnitudes
Aλ The dust extinction at wavelength λ, in magnitudes (Eqs. (5.2) and (5.84))
a The grain size
B(ν, T) The Planck function at frequency ν and temperature T
Bij Einstein B coefficient (Eq. (2.18))
Be (also B, A, C) Rotational constant (Eqs. (2.4), (2.8), (2.9), (2.11))
B0 The preshock magnetic field strength
B1 The postshock magnetic field strength
b The Doppler line-width parameter
CV The heat capacity of the grain material
Cs The speed of sound (Eq. (11.8))
CI The speed of sound in neutral gas
CII The speed of sound in ionized gas
c The speed of light […]
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- The Physics and Chemistry of the Interstellar Medium , pp. 476 - 483Publisher: Cambridge University PressPrint publication year: 2005