Sherpa and CIAO
The Sherpa package was developed by the Chandra X-ray Center (CXC) as a general purpose fitting and modeling tool, with specializations for handling X-ray Astronomy data. It is provided as part of the CIAO analysis package, where the code is the same as that available from the Sherpa GitHub page, with the following modifications:
the I/O backend uses the CIAO library Crates rather than Astropy;
a set of customized IPython routines are provided as part of CIAO that automatically loads Sherpa and adjusts the appearance of IPython (mainly changes to the prompt);
and the CIAO version of Sherpa includes the optional XSPEC model library (
sherpa.astro.xspec
).
The online documentation provided for Sherpa as part of CIAO,
namely https://cxc.harvard.edu/sherpa/, can be used with the
standalone version of Sherpa, but note that the focus of this
documentation is the
session-based API
provided by the
sherpa.astro.ui
and sherpa.ui
modules.
These are wrappers around the Object-Oriented
interface described in this document, and data management
and utility routines.