The Chandra X-Ray Center released version 4.0.2 of the Chandra Interactive Analysis of Observations (CIAO) software package on 16 April 2008.

The CIAO 4.0.2 patch enables CIAO to run on Mac OS X 10.5 (Leopard) Intel. The patch is optional for 10.4 (Tiger) Intel machines.

The patch should not be applied to Linux, Solaris, or Mac PowerPC installations of CIAO.

Download the 4.0.2 patch.

Additionally, there is an updated standalone version of ObsVis for Mac OS X Intel; see the ObsVis website for details and the download.

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(16 Apr 2008) Mac OS X platforms: FITS table file writing slowness with NFS-mounted disks.

FITS table file writing through the CXC Data Model slows by a significant factor on Mac OS X machines - both 10.4 (Tiger) and 10.5 (Leopard) - when the data is accessed via a networked file system (NFS) mount. This issue does not affect Solaris or Linux platforms.

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(31 Mar 2008) CALDB 3.4.3 has been released for use with CIAO 3.4 and 4.0.

Information on the patch is available from the CALDB 3.4.3 Release Notes and How CALDB 3.4.3 Affects Your Analysis.

Download CALDB 3.4.3

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CIAO 4.0 is a full installation of the CIAO software. It contains all the enhancements and bug fixes since CIAO 3.4, including those which were made available in the 4.0 Beta releases.

The most notable change to the CIAO tools in version 4.0 is that the ACIS dead area correction is turned on by default; refer to the How CIAO 4.0 and CALDB 3.4.2 Affect Your Analysis section of the release notes for details. There is a new version of tgextract - named tgextract2 - which provides similar functionality, but allows large and asymmetric regions for better determination of background counts. Significant work has been done on the tool wavdetect, which has two new parameters. The sso_freeze tool has been enhanced so that it can create object-centered aspect solutions which allows an object-centered exposure map to be generated. A number of bug fixes to the Data Model library and several CIAO tools are also included.

The Data Model library now supports an ASCII kernel. This kernel allows users to generate ASCII format files for use within Data Model enabled tools (e.g. dmlist, dmcopy), and apply the suite of Data Model capabilities to those files via its extended filename syntax. The ASCII kernel is considered beta for this release.

The CIAO 4.0 release includes a new, more powerful version of ChIPS, the CIAO plotting package. It can be used during data analysis - e.g. to plot a lightcurve - and to create publication-quality figures. Details and documentation on the new system is available from the ChIPS website.

This release also features an experimental (beta) version of the new Sherpa, the CIAO modeling and fitting package. Details and documentation on the new system are available from the Sherpa website.

CIAO 4.0 is fully GPL compliant. OTS (off-the-shelf) software have been updated to current versions. A set of "smoke test" scripts are included to aid users in verifying installation of the release.

Installation instructions are available on the Downloading CIAO page.

Since CIAO 4.0 is a major release with several new packages and applications, the CXC will continue to support CIAO 3.4 for the near future. We suggest that users who install CIAO 4.0 keep the CIAO 3.4 installation available as well [Why?].