Bug #1198
Incorrect results for fitting of diffuse models
| Status: | Closed | Start date: | 05/13/2014 | |
|---|---|---|---|---|
| Priority: | High | Due date: | 07/01/2014 | |
| Assigned To: |  Martin Pierrick | % Done: | 100% | |
| Category: | - | |||
| Target version: | 00-09-00 | |||
| Duration: | 50 |
Description
The fitted spectral parameters for a diffuse model are incorrect. This was noted by Pierrick in simulations of the LMC and also reported by Akira in studies of Orion molecular clouds. When using a simple power law for the diffuse component, both the prefactor and the spectral index are significantly off the true values.
Note that issue #1248 was open in ctools specifically for Orion.
Recurrence
No recurrence.
Related issues
History
#1
Updated by Knödlseder Jürgen over 10 years ago
- Status changed from New to In Progress
- % Done changed from 0 to 10
This is maybe fixed by the #1151 bug fix, but needs to be checked.
#2
Updated by Martin Pierrick over 10 years ago
- Description updated (diff)
#3
Updated by Martin Pierrick over 10 years ago
Knödlseder Jürgen wrote:
This is maybe fixed by the #1151 bug fix, but needs to be checked.
I confirm that the problem as initially encountered was very likely due to the background fitting, which went wrong when using the IRF background (because of its rough binning) and/or when using a tabulated spectrum and too few bins in a binned likelihood analysis.
Further tests are under way to confirm that now everything is fine. More below...
#4
Updated by Knödlseder Jürgen over 10 years ago
- Target version set to 3rd coding sprint
Hope we can fix this during the 3rd coding sprint, or at least in the days after ...
#5
Updated by Knödlseder Jürgen about 10 years ago
Is this an open issue anymore or can we close that?
#6
Updated by Knödlseder Jürgen about 10 years ago
- Target version changed from 3rd coding sprint to 00-09-00
#7
Updated by Martin Pierrick about 10 years ago
On my side things are now OK, at least for the cases I have worked on. Note however that I never tried the new IRF background with rebining, so cannot guarantee that this is safe (I kept working with tabulated spectra and gaussian profiles).
#8
Updated by Knödlseder Jürgen about 10 years ago
- Status changed from In Progress to Closed
- % Done changed from 10 to 100
Close that now.