A User's Guide to Reducing CGS4 Data with IRAF

This document presents methods that can be used to reduce CGS4 data with IRAF. These methods were developed to maintain consistency with CGS4DR and Figaro, two software packages that have been used to reduce CGS4 data. Scripts are also presented that will simplify the data reduction process.

Also included in this document is a sample run-through that will guide the reader through a typical data reduction process.

All files needed for the reduction of CGS4 data can be downloaded from the Files page. This document is also available as a PostScript file for local printing.

• Contents
• List of Figures
• Introduction
  • The Basics of Data Reduction
  • Typographical Notes
    • Notation Examples
  • File Naming Convention
    • Bad Pixel Masks
  • Directory Names
• Directory and File Set-Up
  • Directories
  • Files
• Data Reduction
  • Parameters Common to All Tasks
  • Bias Reduction - The biasred task
  • Dark Reduction - The darkred task
  • Flat Reduction - The flatred task
  • Arc Reduction - The arcred task
  • Object Reduction - The objred task
• Spectrum Extraction and Calibration
  • Spectrum Extraction
  • Wavelength Calibration
  • Flux Calibration
• Comparison With Previous Results
• Sample Run-Through
  • Set-Up
  • Data Reduction
  • Spectrum Extraction
  • Wavelength Calibration
  • Flux Calibration
  • Final Spectrum
• File Listings
  • Bad pixel mask fpa46_short.txt
  • Bad pixel mask fpa46_5mic.txt
  • Script for the arcred task
  • Script for the biasred task
  • Script for the darkred task
  • Script for the flatred task
  • Script for the irflux task
  • Script for the objred task
• References and Further Reading
• Troubleshooting
• About this document ...