Appendix B
A Step-by-Step Guide to Spectral-Line Data Analysis in AIPS

Initially contributed by Andrea L. Cox and Daniel Puche

In this guide, we assume that the reader is familiar with the basic tools of AIPS; e.g.MCAT (3.3), GETN (3.3.1), IMHEAD (3.3.4) and other AIPS tools involving the manipulation of the data catalog are not mentioned. This guide contains three main sections covering editing and calibration of spectral-line data, making and Cleaning of map cubes, and moment analysis and rotation curves of galaxies. It is assumed through these sections that all sources in the data set were observed at the same frequency; the final section of this guide describes what you should do before beginning data reduction if this is not the case.

This is an outline of a typical reduction procedure for spectral-line data from the VLA; different users may use slightly different approaches. This guide is a supplement to the AIPS EXPLAIN and ABOUT verbs (3.8) and the AIPS CookBook. Some of the less obvious or more important parameters for each task will be mentioned, but the user should always check to ensure that the rest of the parameters are specified correctly. When in doubt, the defaults are usually fairly safe. Words in boldface or typewriter fonts represent AIPS tasks and their inputs. When you see a phrase enclosed in brackets, replace the phrase and the brackets with the correct input. For example, to specify the source 0134+329

     SOURCE < source_name >would be typed as

     SOURCE ’0134+329’ The text below is in a three-column format, showing a step number on the left, a descriptive paragraph in the center, the name of the AIPS task or verb on the right.

 B.1 Editing and calibrating spectral-line data
  B.1.1 Loading the data
  B.1.2 Inspecting and editing the data
  B.1.3 Calibrating the data
 B.2 Making and Cleaning image cubes
 B.3 Moment analysis and rotation curve of galaxies
 B.4 Multi-frequency observations
  B.4.1 General frequency information
  B.4.2 Multi-frequency uv files
 B.5 Additional recipes