Instrument Model Bugs: farf1d

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11 Nov 2008

These are the webpages relative to Sherpa in the CIAO 3.4 release (18 December 2006). They are no longer actively updated, however the CXC will continue limited support of CIAO 3.4 for the near future.

15 Dec 2008

The newest version of the Chandra Interactive Analysis of Observations software, is CIAO 4.1, released on 15 December 2008. Read the release notes for detailed information. This release requires that CALDB 4.1.0 be installed for the software to work correctly.

Bugs

Sherpa is unable to change the instrument model in ARF-only mode.

sherpa> farf1d[a1](src1.arf)
The inferred file type is ARF.  If this is not what you want, please 
specify the type explicitly in the data command.

sherpa> farf1d[a2](src2.arf) 
The inferred file type is ARF.  If this is not what you want, please 
specify the type explicitly in the data command.

sherpa> instrument 1 = a1 

sherpa> instrument 1 = a2 
Error: illegal instrument definition.
       Mapping from ARF to PHA bin unknown - provide RMF.
       Instrument definition deleted.

Workaround:

it is necessary to erase the first ARF in order to assign the second one:

sherpa> erase data 1 
sherpa> instrument 1 = a2

Note that simply clearing the instrument model stack does not work in this case.