Chandra Announcements: CIAO/Sherpa 4.12.1 release; CalDB 4.9.2.1 upgrade Revision A file released

[Tara Gokas]

CIAO/Sherpa 4.12.1 released on 14 Jul 2020

CIAO 4.12.1 has been released with a new version of Sherpa (Sherpa 4.12.1).  This Sherpa release provides fixes to bugs that would stop an analysis session or provide incorrect results. Apart from Sherpa, CIAO 4.12.1 is identical to CIAO 4.12.

The major updates in this Sherpa release include:

• load_multi_arfs and load_multi_rmfs - caching fixed. It would otherwise prevent fit from running when using multi-order responses in modeling grating spectra.

• calc_photon_flux and calc_energy_flux enhanced to better handle monochromatic flux densities and fluxes where the energy bounds fall in between the model grid bin edges. A new model argument is also added to calculate "unabsorbed" fluxes by specifying specific model components.

• model caching is now optional.

The Release Notes contain more details about the release.  Sherpa in CIAO runs under Python version 3.5 (when installed with ciao-install) or Python 3.7, 3.6, or 3.5 (when installed using the conda package manager). 

The Sherpa 4.12.1 standalone release including the source code is available via Sherpa github repository. Up to date documentation pages with source installation instructions are available on Sherpa RTD page.

A Note to users of CIAO 4.12 and the CalDB 4.9.2.1 upgrade:

Notice: CalDB 4.9.2.1 "upgrade" file Revision A released:

The following information is available on the Download CalDB 4.9.2.1 Web page at:

https://cxc.cfa.harvard.edu/caldb/downloads/index.html#Notice_4.9.2.1_revA

The CXC Help Desk has become aware that some users are having a problem with the CalDB 4.9.2.1 upgrade tar file, named caldb_4.9.2.1_upgrade.tar.gz, which was released on 09 July 2020. The trouble was due to a redundant listing of a particular CalDB file in the seed MANIFEST file used to build it, which "gtar" had innocuously loaded as a link to the previous listing. For users with more basic "tar" commands installed, this causes the repeated file to be deleted by a "self-referring link" error. "gtar" and more advanced "tar" commands on the other hand give no problems at all unpacking this tar file.

We have corrected the MANIFEST and the upgrade tar file nonetheless, to a "revA" version, and made it available for download to correct this issue. The CalDB 4.12 ciao-install procedure already uses the corrected "upgrade" file when appropriate, and the fix is transparent. However, for users who have already run ciao-install, and have experienced the missing file, ciao-install will not correct the situation for you.

If you ran ciao-install before 14 July 2020 2:00 PM EDT (UTC 2020-07-14T18:00:00), downloaded caldb_4.9.2.1_upgrade.tar.gz, and have only a basic version of "tar" on your system for unpacking tar files, you may have been affected by this issue. Please see the link above for a short set of instructions to determine if this is the case, and how to fix the problem if you have it.

As always, please send questions and requests for enhancements to the CXC HelpDesk (http://cxc.harvard.edu/helpdesk/).