For convenience, the individual FTOOLS tasks are collected together in "sub-packages." Thus, the tasks that perform generic functions that could be appropriate for any type of FITS file (e.g., list the contents of a FITS file and write it to another FITS file), are distiguished from the mission-specific tasks that perform calibration or analysis functions on various kinds of high-energy astrophysics data.

General Subpackages

The following General subpackages are currently available:

Package Description
attitude Multi-mission attitude tasks
caltools General Calibration Tasks
fimage General FITS Image-Manipulation Tasks
futils General-Purpose FITS Tasks
heagen Next-generation multi-mission tasks
heasarc General Tasks for High Energy Astrophysics (includes Xselect)
heasim Multi-mission high-energy astrophysics simulation tool
heasptools Next-generation spectral analysis tools
heatools Next-generation futils
time Timing-Specific Tasks
xronos The HEASARC's general timing analysis package

Mission-Specific Tasks

The following subpackages are currently available for specific missions:
  • asca - ASCA Mission-Specific Tasks
  • cgro - CGRO Mission-Specific Tasks
  • einstein - Einstein Mission-Specific Tasks
  • exosat - EXOSAT Mission-Specific Tasks
  • heao1 - HEAO 1 Mission-Specific Tasks
  • hitomi - Hitomi Mission-Specific Tasks
  • integral - Integral Mission-Specific Tasks
  • maxi - MAXI Mission-Specific Tasks
  • nicer - NICER Mission-Specific Tasks
  • nustar - NuSTAR Mission-Specific Tasks
  • oso8 - OSO8 Mission-Specific Tasks
  • rosat - ROSAT Mission-Specific Tasks
  • suzaku - Suzaku Mission-Specific Tasks
  • swift - Swift Mission-Specific Tasks
  • vela5b - Vela 5b Mission-Specific Tasks
  • xte - XTE Mission-Specific Tasks


Xselect is a general driver which greatly simplifies many commonly performed tasks such as extracting images or spectra from events files. Xselect is distributed with the HEASARC package on the download page.


Since v4.0, FTOOLS has had a new emphasis on graphical interfaces to the ftools. While the old command line functionality is still there for scripting or for those who just really like it, we encourage you to try the new interfaces; they may make your life a lot easier. The current GUI tools are:

  • fv - A graphical FITS file editor for both tables and images.
  • xdf - The XTE data finder. Allows easy traversal of an XTE data directory tree.
  • xsut - XSUT is a tool designed by the RXTE GOF as a graphical front-end to the GNU tar program to help in selectively untarring RXTE (and RXTE only) data tapes or tar files


If FTOOLS has been useful in your research, please reference this site ( and use the ASCL reference for HEASoft [ascl:1408.004] or the ASCL reference for the original FTOOLs paper [ascl:9912.002]:

Blackburn, J. K. 1995, in ASP Conf. Ser., Vol. 77, Astronomical Data Analysis Software and Systems IV, ed. R. A. Shaw, H. E. Payne, and J. J. E. Hayes (San Francisco: ASP), 367.

Web page maintained by: Bryan K. Irby