Skip to the navigation links
Search the CIAO website or contact the CXC HelpDesk
Last modified: 19 January 2010

URL: http://cxc.harvard.edu/ciao4.2/index.html
[CIAO logo]

from "s'sciavo", "I am your servant" in Venetian dialect*

WHAT'S NEW | WATCH OUT
Quick CIAO links: Download CIAO | Science Threads | Help Files | Scripts
Related CXC sites: ChIPS | Sherpa | PSFs with ChaRT | CALDB
Chandra Source Catalog | TGCat: Chandra Gratings Catalog

Download CIAO 4.2 and CALDB 4.2.0: the newest versions of the Chandra Interactive Analysis of Observations software and the Chandra Calibration Database, released on 15 December 2009.

Read the CIAO 4.2 release notes for detailed information on this release.

  • The Sherpa modeling and fitting package has a number of enhancements including a new algorithm for calculating confidence, simulations to probe model parameter space and calculate flux uncertainties, full support for wavelength analysis, and a "save_all" command to save the session in ASCII format. It also has capabilities to run parallel processing. Refer to the Sherpa Latest Updates page for more information.

  • The ChIPS plotting application includes beta support for displaying images and colorbars, as well as the ability to create an editable ASCII save file.

  • Two new tools - create_bkg_map and dmimgpm - enable users to create spatial background maps equivalent to those in the Chandra Source Catalog and useful for for source detection and for detection sensitivity maps.

  • acis_build_badpix allows users more control over customizing the bad pixel files.

  • hrc_process_events, combined with files released in CALDB 4.2.0, can apply time-variable gain calibrations. Using the gain-corrected PI values can reduce the background.

  • tg_create_mask has improved the custom mask settings.

The CIAO 4.2 software requires CALDB 4.2.0 to work correctly. Information on the CALDB 4.2.0 release is available from the CALDB 4.2.0 Release Notes and How CIAO 4.2 and CALDB 4.2.0 Affect Your Analysis.

Transitioning to ChIPS and Sherpa in CIAO 4

The CXC is committed to helping CIAO users transition to the new ChIPS and Sherpa syntax as smoothly as possible. If you have existing scripts or save files from CIAO 3, submit them to us via the CXC Helpdesk and we will provide the CIAO 4 equivalent.

Please be sure to tell us if you are working in S-Lang or Python, and place the relevant data files on the FTP (FTP Instructions).

I've never used CIAO before. Where should I begin?

Welcome to CIAO
Introduction to the Tools & Applications

Platform Support

Download CIAO 4.2
Installing CIAO 4.2 thread

Introductory Science Threads

Analysis Guides

Has a new version of CIAO or CALDB been released?
What has changed in the site recently?

What's New

"Watch Out" List

Version History

CIAO Release Notes
CALDB Release Notes

CIAO isn't working correctly - I need help!

CIAO Software Help Pages

Frequently Asked Questions (FAQ)

Known CIAO Bugs and Tool Caveats

CXC Helpdesk

I am an expert CIAO user. Where can I find more detailed information?

Why Topics

Manuals

Scripting in CIAO

Citing CIAO in a Publication

If you are writing a paper and would like to cite the CIAO software, we recommend the following:

CIAO: Chandra's data analysis system (ADS, PS)
Fruscione et al. 2006, SPIE Proc. 6270, 62701V, D.R. Silvia & R.E. Doxsey, eds. 

\bibitem[Fruscione et al.(2006)]{2006SPIE.6270E..60F} Fruscione, A., et 
al.\ 2006, \procspie, 6270

The specific version of CIAO and CALDB used for the analysis should be mentioned. Further guidelines are available from the Acknowledgment of Use of Chandra Resources.

About this Website

The paper "The CIAO Website Unveiled" (ADASS XIV, 2004) describes the infrastructure of this website.


Last modified: 19 January 2010