National Aeronautics and Space Administration

An X-Ray Spectral Fitting Package

Version 12.13.1 Now Available

Helpful information available includes:

• Frequently Asked Questions
• Download and installation instructions
• Xspec release notes
• Xspec wiki
• Xspec internal functions guide
• Xspec facebook group [external]
• External Resources
• Xspec v11
• Details of Xspec redesign
  A site section displaying the design details and implementation of Xspec version 12.

Download the full Xspec manual.

• Manual in Portable Document Format (PDF)
  Adobe Acrobat (link to free reader download)
• Manual in HTML format

The latest Xspec reference is Arnaud, K.A., 1996, Astronomical Data Analysis Software and Systems V, eds. Jacoby G. and Barnes J., p17, ASP Conf. Series volume 101.

Xspec 12 was developed by Keith Arnaud, Ben Dorman, and Craig Gordon,
HEASARC Software Development, Astrophysics Science Divsion,
Code 660.1, NASA/GSFC, Greenbelt MD 20771

Please send comments, questions, and bug reports to xspec12@athena.gsfc.nasa.gov