Starlink Project
Starlink Guide 9.2

Martin Clayton

11 December 1996

Introduction to Echelle Spectroscopy


1 Introduction
 1.1 Other Sources of Information
2 An Echelle Spectrum
3 Preparing for Observation
 3.1 What CCD Data Do You Need?
 3.2 Detector Pre-processing
 3.3 Flat Fields
 3.4 Order Tracing
 3.5 Wavelength Calibration
 3.6 Flux Calibration
4 The Basics of Echelle Data Reduction
 4.1 Image Preparation
  4.1.1 Software for CCD Data Preparation
 4.2 Order Location
 4.3 Order Tracing
 4.4 Slit Definition
 4.5 Flat Fielding
 4.6 Background Handling
 4.7 Extraction of Spectra
 4.8 Wavelength Calibration
 4.9 Finishing Reduction
  4.9.1 Blaze Correction
  4.9.2 Flux Calibration
  4.9.3 Re-binning Spectra—Scrunching
  4.9.4 Combining Orders—Merging
 4.10 Handling Cosmic Rays
5 Data Reduction Facilities
 5.1 Available Packages
 5.2 Choosing a Package
6 Glossary


[1]   L. Achmad and L. Pasquini,
CASPEC Thorium-Argon Atlas in the 3050–3650Å Region,
ESO Document ASD-MAN-SCI-000-001, May 1995.

[2]   S. D’Odorico, M. Ghigo and D. Ponz,
An Atlas of the Thorium-Argon Spectrum for the ESO Echelle Spectrograph in the λλ 3400–9000Å Region,
ESO, 1987.

[3]   Michael Bessell and Max Pettini,
UCLES Spectrum of the Thorium-Argon Hollow-Cathode Lamp,
AAO UM 28.1, January 1991.

[4]   Christopher W. Churchill,
Introduction to Echelle Data Reduction Using the Image Reduction Analysis Facility,
Lick Observatory Technical Report No. 74, February 1995.

[5]   Christopher W. Churchill and S. L. Allen,
A Treatment for Background Correction on the Hamilton Echelle Spectrograph,
pp. 193–198, Pub. A. S. P. Vol. 107, February 1995.

[6]   Martin Clayton,
Echelle data reduction cookbook,
Starlink Cookbook 3.1, January 1996.

[7]   Malcolm J. Currie,
KAPPA — Kernel Application Package,
Starlink User Note 95.8, August 1992.

[8]   Peter W. Draper,
CCDPACK — CCD data reduction package,
Starlink User Note 139.4, November 1995.

[9]   Keith Horne,
An Optimal Extraction Algorithm for CCD Spectroscopy,
pp. 609–617, Pub. A. S. P. Vol. 98, June 1986.

[10]   Image Processing Group, ESO,
MIDAS Users Guide,
Volumes B. and C., November 1994.

[11]   Tom Marsh,
The Extraction of Highly Distorted Spectra,
pp. 1032–1037, Pub. A. S. P. Vol. 101, November 1989.

[12]   Philip Massey,
A User’s Guide to CCD Reductions with IRAF,
Central Computer Services, NOAO, June 1992.

[13]   Horst Meyerdierks,
FIGARO – A general data reduction system,
Starlink User Note 86.10, October 1995.

[14]   Dave Mills, John Webb and Martin Clayton,
ECHOMOP – Echelle data reduction package,
Starlink User Note 152.2, December 1995.

[15]   Koji Mukai,
Optimal Extraction of Cross-Dispersed Spectra,
pp. 183–189, Pub. A. S. P. Vol. 102, February 1990.

[16]   J. G. Robertson,
Optimal Extraction of Single-Object Spectra from Observations with Two-Dimensional Detectors,
pp. 1220–1231, Pub. A. S. P. Vol. 98, November 1986.

[17]   Francisco Valdes,
Guide to the Slit Spectra Reduction Task DOECSLIT,
Central Computer Services, NOAO, April 1992.

[18]   Francisco Valdes,
Guide to the Multifiber Reduction Task DOFIBERS,
Central Computer Services, NOAO, April 1992.

[19]   Francisco Valdes,
IRAF Tutorials: Echelle Slit Reductions with DOECSLIT,,
April 1994.

[20]   Daryl Willmarth and Jeannette Barnes,
A User’s Guide to Reducing Echelle Spectra With IRAF,
Central Computer Services, NOAO, May 1994.