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Last modified: 27 September 2010

[CIAO logo]

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

Install CIAO 4.2 and CALDB 4.3.1: the newest versions of the Chandra Interactive Analysis of Observations software and the Chandra Calibration Database.

The CIAO 4.2 software requires CALDB 4.2.0 or higher to work correctly. Read the CIAO 4.2 release notes for detailed information on this release.

Upgrade to Sherpa v2: an update to the Sherpa package in CIAO 4.2.

[New] Released on 19 July 2010, v2 of the Sherpa package has a number of enhancements, such as two new iterative fitting methods, refinements to parallelization, and many improvements to instrument and source models. Read the CIAO 4.2 Sherpa v2 release notes. (Sherpa v2 is not available on Mac OS X 10.4 PPC.)

Upgrade to CALDB 4.3.1: for users who already have CALDB 4.2.x installed.

Released on 28 Sept 2010, the CALDB 4.3.1 upgrade contains new ACIS time-dependent gain files and updates to the ACIS blank-sky background files. More information is available from the CALDB Release Notes and How CALDB 4.3.1 Affects 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.

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


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: 27 September 2010