Chapter 8 Spectral Analysis Observational Astrophysics

Abstract

Spectroscopy is at the heart of astrophysics, and indeed, it is usually spectroscopic observations and their interpretation which provide the strongest constraints on the models proposed by astrophysicists. There are a great many examples: energy balance, abundance of molecules, atoms, ions, or other particles, macroscopic or microscopic velocity fields, local physical conditions such as the temperature, the density, the magnetic or electric fields, states of equilibrium or of deviation from equipartition of energy, and so on.