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Last modified: 24 October 2023


Other Software for Chandra Data Analysis

There are many other tools that can work with Chandra data. On this page we provide links to some of the software of which we are aware, developed both by the CXC and by external users. They are divided into three broad categories of large packages, science tools, and general-purpose infrastructure.

If you are the developer or maintainer of a program or package that you think should be on this page, or if the information about your package is incorrect, please contact the CXC Helpdesk.

Please note that the CIAO HelpDesk does not provide support for this software. If you need help using one of these packages, contact the package maintainer listed on the package's website.

Analysis Packages

ACIS Extract

Developed by Pat Broos et al., Penn State

Suite of analysis tools for analysing ACIS data.



Developed by many people at NASA-GSFC

General X-ray data analysis; includes XSPEC (Keith Arnaud et al.) for x-ray spectral fitting and FTOOLS (Bill Pence et al.) for general data manipulation.

Spectral Analysis Tools


Developed by John Houck, MIT-CXC

X-ray spectral analysis system

Requirements: PGPLOT, CFITSIO, S-Lang


Developed by Jeremy Drake, SAO-CXC

X-ray spectral analysis system with atomic databases.

Requirements: IDL


Maintained by Doug Burke, created by Tom Aldcroft, SAO-CXC.

CIAO Sherpa extension package to facilitate deprojection of two-dimensional annular X-ray spectra to recover the three-dimensional source properties of the optically-thin plasma in Galaxy clusters, groups, and galaxies.

Requirements: Sherpa

He-like Ion Line Emissivities for X-Ray Spectral Modeling

Developed by David Huenemoerder and John Houck, MIT

FITS tables and scripts which provide density-dependent emissivities of the He-like triplets (both electron density for collisional excitation, or UV energy density for photoexcitation).

Requirements: ISIS (for plasma modeling in conjunction with APED) or fitsio (for standalone use).


Developed by Jelle Kaastra, SRON

X-ray spectroscopic analysis

Requirements: PGPLOT


Developed by Randall Smith, GSFC

Profit is a GUI (graphical user interface) tool for accessing high-resolution spectra. Profit displays spectra in various formats, allowing users to identify emission lines, to convert an identified line into velocity units using a user-selected wavelength, to store (and restore) individual spectra, to fit lines to gaussians, and other features.

Specialized Science Tools


Developed by the CXC Optics Group

A suite of software designed to simulate the as-built performance of grazing-angle X-ray optics using the ray-tracing approach. Configuration data for Chandra is available.

Requirements: SAOTrace External Dependencies


Developed by Mike Nowak, MIT-CXC

Chandra timing analysis

Requirements: ISIS

Subpixel Event Repositioning Algorithms

Developed by Joel H. Kastner (Rochester Institute of Technology)

Subpixel Event Repositioning (SER) techniques have been demonstrated to significantly improve the already unprecedented spatial resolution of Chandra X-ray imaging with the Advanced CCD Imaging Spectrometer (ACIS). Chandra CCD SER techniques are based on the premise that the impact position of events can be refined, based on the distribution of charge among affected CCD pixels.

Requirements: IDL, CIAO



Developed by Eric Mandel, CfA

An image viewer (for FITS files) that operates in your web browser or desktop.

Requirements: Javascript / web browser.


Developed by Eric Mandel, CfA

Tools for manipulating FITS files, including X-ray binary tables

Requirements: none

S-Lang HDF5 Module

Developed by Michael Noble, MIT-CXC

SLh5 is a S-Lang module for the HDF5 file format and software library. HDF5 is widely used in large scale science and engineering projects - such as the FLASH simulator of thermonuclear explosions in stars - because it combines data and compiler portability with very high performance, scalability to terabyte-size datasets, and support for parallel I/O.

Requirements: HDF5, S-Lang, and SLIRP


Developed by Michael Noble, MIT-CXC

SLIRP generates automatic S-Lang wrappers for C, C++ or Fortran code.

Requirements: S-Lang


Developed by Doug Burke, SAO-CXC. This is no-longer in development.

Inline::SLang is a perl module which generates Perl wrappers for S-Lang code.

Requirements: S-Lang, Perl

S-Lang GTK widget wrappers

Developed by Michael Noble, MIT-CXC

The SLgtk package wraps the GIMP toolkit widget set (Gtk) for use in S-Lang, and provides a simple and modular way of adding graphical interfaces to applications without recoding them from scratch as GUIs. SLgtk bundles scores of guilets, ranging in function from simple buttons and screen drawing all the way to through plotting and imaging of FITS files. SLgtk also includes the powerful VWhere data explorer and the multi-image-format imdisplay tool.

Requirements: S-lang, GTK