1 Other Sources of Information

This cookbook complements the Starlink Introduction to Echelle Spectroscopy (Starlink document SG/9) which is a good first read for those new to échelle work.

A significant part of the process of successful spectrum extraction is the preliminary handling of the CCD data frames. Those planning to use IRAF1 should consult A User’s Guide to CCD Reductions with IRAF (UGCRI) by Philip Massey. UGCRI is quite a good document for any user of CCD data, even those planning to use e.g. CCDPACK or FIGARO, to do the preparation.

IRAF users should look at the two documents for échelle data reduction within IRAF: A User’s Guide to Reducing Echelle Spectra With IRAF and Guide to the Slit Spectra Reduction Task DOECSLIT. These give a comprehensive description of the IRAF approach to échelle data. There is also a hypertext tutorial for DOECSLIT at

You may be able to access a local copy of this tutorial; consult your system manager.

There is an excellent guide tailored to the reduction of échelle data taken using the Hamilton Spectrograph: Introduction to Echelle Data Reduction Using the Image Reduction Analysis Facility, which is a Lick Observatory Technical report. (A PostScript copy is available from the Starlink Echelle Support Pages.) This is a complete step-by-step run through of échelle data reduction using IRAF – from CCD data to calibrated spectra.

The primary documentation for ECHOMOP is ECHOMOP – Echelle data reduction package (Starlink document SUN/152). This document explains each of the data reduction steps using ECHOMOP and includes some general advice and tips. There is some additional information and advice in the on-line HELP for ECHOMOP if you get stuck.

An up-to-date set of hypertext documents for Starlink échelle data reduction and related information; including hypertext help, bug reports, comments and news is maintained at

The absolute latest version of this document is also kept in these pages. All the scripts included here are available in source form.

1IRAF documents can be found in your IRAF installation; you do not need to get them from Tucson or a mirror. Check with your manager for details.