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Last modified: 26 October 2010


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 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.


Developed by Alexey Vikhlinin, CfA

Collection of X-ray analysis tools for image analysis

Requirements: fitsio, WCStools

Specialized Science Tools


Developed by Jennifer Posson-Brown (SAO), Catherine Grant (MIT), Glenn Allen (MIT), Paul Plucinsky (SAO), Richard Edgar (SAO), Dale Graessle (SAO) and the ACIS calibration team

Apply a temperature-dependent CTI correction to ACIS data. This calibration will be included in version 4.3 of CIAO (December 2010).

Requirements: IDL, CIAO


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 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


Developed 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.

Requirements: CIAO


Developed by Jelle Kaastra, SRON

X-ray spectroscopic analysis

Requirements: PGPLOT


Developed by Andy Ptak, JHU

Automated processing of a field to generate a list of sources and their properties.

Requirements: HEASOFT, CIAO


Developed by Mike Nowak, MIT-CXC

Chandra timing analysis

Requirements: ISIS


Developed by Randall Smith, GSFC

High resolution spectroscopy



Developed by Steven Diehl and Tom Statler, Ohio University

WVT Binning is an adaptive binning method, designed to handle sparse X-ray data. The algorithm is a generalization of Cappellari and Copin's Voronoi binning method, which was designed for integral field spectroscopy.

Requirements: IDL

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



Yaxx (Yet Another X-ray Xtractor) is a Perl script that facilitates batch spectral processing of Chandra data using CIAO tools, Sherpa, S-lang, and Perl open source software. It includes automated spectral extraction, fitting, and report generation.

Requirements: Perl v. 5.8.0 or newer, CIAO 3.4 or newer, LaTeX (optional)

Developed by Tom Aldcroft, CXC

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

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

Requirements: S-Lang, Perl


Developed by Eric Mandel, CfA

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

Requirements: none

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

Last modified: 26 October 2010