14

SC/8.1

Starlink Project
Starlink Cookbook 8.1

Henry Matthews, Tim Jenness

1st March 1997

Specx Cookbook
Reduction of millimetre wave data

pdfpict

Abstract

This cookbook provides an introduction to the facilities found in the SPECX data reduction package.

Contents

1 A SPECX “Cookbook”
2 Rapid Introduction to SPECX
 2.1 Start-up
 2.2 Initialization
 2.3 Looking at spectra
 2.4 Averaging spectra
 2.5 Dealing with DAS spectra: basics
 2.6 Sending plots to laser printer
 2.7 Saving the results
 2.8 Retrieving data
 2.9 Fitting and removing baselines
 2.10 Making maps
 2.11 Displaying Map Data
 2.12 Some other things
 2.13 And now…
3 A More Complete Introduction to SPECX
 3.1 Finding your data
 3.2 Getting into SPECX
 3.3 Things to know about SPECX
  3.3.1 Selecting output and input.
 3.4 Getting the data
  3.4.1 Closing in on your spectrum; interactive vs non-interactive modes
 3.5 A note on command line syntax
 3.6 Dressing Up Your Spectrum
  3.6.1 Smoothing the data
  3.6.2 Putting vertical and horizontal lines on the spectrum
 3.7 Getting To Know Your Baselines
  3.7.1 Linear baselines
  3.7.2 Polynomial baselines
  3.7.3 Gaussian models
 3.8 The Stack
 3.9 Saving Reduced Data for later
  3.9.1 Using Data Files
  3.9.2 Temporary Storage
 3.10 Using das-merge
  3.10.1 The Principles
  3.10.2 Caveats
 3.11 Dealing With Multiple Spectra
  3.11.1 Averaging Several Spectra
  3.11.2 Displaying More Than One Spectrum
 3.12 Concatenation – combining spectra lengthwise
  3.12.1 Making very long spectra
  3.12.2 The special case of the 750-MHz mode
 3.13 Arithmetic With Spectra
  3.13.1 Spectrum Statistics
 3.14 Dealing with spikes
 3.15 Writing Your Own Command Files
  3.15.1 The Basics
  3.15.2 Repetitive Operations
  3.15.3 Automatic Repetitive Operations
  3.15.4 In-line do-loops
 3.16 Modifying the Velocity and Frequency Axes
  3.16.1 set-x
  3.16.2 s-l-r-f, s-v-f and ch-sid
 3.17 Reduction of frequency-switched data
 3.18 Hardcopy and file output
 3.19 Making Maps
  3.19.1 Getting The Parameters Right
  3.19.2 Map Files
  3.19.3 Dealing with lines in the other sideband
  3.19.4 The read-gsd-raster routine
  3.19.5 Grid Spectra
  3.19.6 Contour Plots
  3.19.7 Color ‘grayscale’ images
  3.19.8 Channel Maps
 3.20 Data format conversion
  3.20.1 Conversion of older VMS SPECX data to Unix-readable format
  3.20.2 Conversion to ASCII files
  3.20.3 Conversion of single spectra to FITS format
  3.20.4 Conversion of map cubes to FITS
 3.21 Help