Chandra Announcement: CIAO Contributed Scripts and Modules Version 4.18.2 released
Tingle, Evan
CIAO Contributed Scripts and Modules Version 4.18.2 released
The CIAO contributed scripts package version 4.18.2 has been released. This release is driven by the introduction of the crisscross script and its companion script clean_spec, as well as new tools that help visualize and assess fine_astro source matching results. The release also includes numerous minor bug fixes and enhancements. A complete list of changes is available on the contributed scripts history page, with highlights including:
![[New]](https://groups.google.com/a/cfa.harvard.edu/group/chandra-announce/attach/7f475a9a9335d/image.jpeg?part=0.3&view=1)
crisscross and clean_spec are used in concert with each other to greatly simplify the analysis of HETG data with multiple sources present in an observation by identifying regions of each spectrum that may be contaminated with events from other sources. A Jupyter notebook tutorial thread demonstrating the use of crisscross is available at: https://cxc.cfa.harvard.edu/ciao/threads/crisscross/crisscross.html.The fine_astro output now includes additional files per observation in the "xmatch" sub-directory. These are generated by the newly released
![[New]](https://groups.google.com/a/cfa.harvard.edu/group/chandra-announce/attach/7f475a9a9335d/image.jpeg?part=0.1&view=1)
parse_wcs_match_log and ![[New]](https://groups.google.com/a/cfa.harvard.edu/group/chandra-announce/attach/7f475a9a9335d/image.jpeg?part=0.2&view=1)
xmatch_viz scripts, which help visualize which sources are matched to determine the refined astrometric correction.![[New]](https://groups.google.com/a/cfa.harvard.edu/group/chandra-announce/attach/7f475a9a9335d/image.jpeg?part=0.4&view=1)
sherpa_contrib.load_hetg_resp now provides a load_gratings_pha2 method to simplify loading type II PHA gratings data and responses into Sherpa. This new Sherpa contrib function automatically finds and loads the response files, ARFs, and RMFs associated with a Chandra HETG or LETG PHA2 spectral file. dax now includes the standard deviation of the pixel values in the report by the Statistics (dmstat) task.
will now proceed to generate weighted responses even if there are zero counts in the corresponding extraction region rather than erroring out if resp_pos=REGION.
offers improved handling of large input stacks.
flux_obs/merge_obs has improved handling of large input stacks and performs checks to prevent generating computationally expensive data products if there is insufficient system memory available to run to completion.
What version of the contributed package do I have installed?
The following command gives the installed version of the contributed package:
% ciaover -v | grep -i contrib
If the output does not match the following then an update or installation is needed:
Contrib : Package release 2 Thursday, July 9, 2026
The check_ciao_version script can also be used (if the contributed package is installed).
How do I upgrade (or install) the package?
For CIAO installed with the ciao-install script, the contributed package can be upgraded with the same script: please see
https://cxc.harvard.edu/ciao/download/ciao_install.html
Users of the conda installation can update the contributed scripts package by running the following, where <env> is the name of the conda environment where CIAO is installed:
% conda update -n <env> -c https://cxc.cfa.harvard.edu/conda/ciao ciao-contrib
Users of the CIAO DMG disk image (macOS only) can find the updated DMG file at https://cxc.cfa.harvard.edu/ciao/download/ciao_dmg.html