Back to Volume
Paper: Spectral Line Advanced Topics
Volume: 278, NAIC-NRAO School on Single-dish Radio Astronomy: Techniques and Applications
Page: 209
Authors: Dickey, John M.
Abstract: This lecture is in three parts. The first gives the fundamental equations of level populations and radiative transfer which govern spectral line emission and absorption. Lines in the cm-wave band have similarities which allow us to simplify the equations. The further simplification of a two level system (a good approximation for HI) gives the familiar formulae for the 21-cm line. The second part of the lecture deals with mapping, and the combination of single-dish and interferometer data. We consider the effect of gridding single-dish data using a convolving function. Mapping speeds and techniques are discussed. The third part discusses the spectral line cube and its moments. The use of the first moments to determine the dynamical structure of a disk is discussed. The need for windowing in the cube before computing moments is justified.
Back to Volume