1. Towards a CTA high-level science analysis framework
CTA as a community tool - requirements
base science analysis framework on experience gained from other high-energy observatories (Fermi, INTEGRAL, Chandra, XMM, Swift, …)
use wide spread data formats (FITS, VO)
use widely used user interfaces (e.g. IRAF parameter files, XML formats)
break down science analysis into analysis steps (executables)
CTA analysis based GammaLib toolbox
GammaLib: generic, self-contained, open source, multi-platform C++ library for instrument independent high-level science analysis of gamma-ray data
Easy installation: ./configure & make install
No library dependencies = cheap maintenance
Developed by CESR based on former experience with COMPTEL, INTEGRAL & Fermi
Currently at prototype stage
Yellow = prototype exists

2. Possible high-level science analysis schemes
Use GammaLib as C++ API
Analysis executables (ctatools) use GammaLib services
Possible scheme à la Fermi :
Script GammaLib (python)
Access GammaLib services directly
Working example: fitting the Crab using a model define in XML file (à la Fermi)
$ python
>>> from gammalib import *
>>>
>>> run = GCTAObservation()
>>> run.load_binned("cntmap.fits.gz")
>>> run.response("kb_E_50h_v3", "/cta/irf")
>>> obs = GObservations()
>>> obs.append(run)
>>> models = GModels("model.xml")
>>> obs.models(models)
>>> opt = GOptimizerLM()
>>> opt.max_iter(1000)
>>> obs.optimize(opt)
>>> print obs
Prefactor: 1.269e-08 +/ e+00
Index: e+00 +/ e+00
Yellow = prototype exists

3. Status summary and Next steps
Prototype GammaLib software for most components is available
Prototype CTA and Fermi-LAT instrument interfaces are implemented
Several prototype CTA analysis tools are written
Simple CTA data analysis possible (point source fitting)
Next steps
Add the few missing core components to GammaLib (e.g. logging I/F)
Enhance existing GammaLib core components (extended sources, more complex spectral laws, parameter error estimation)
Enhance CTA instrument interface (more realistic response functions, include background handling)
Add CTA analysis tools to complete analysis chain
Conclusions
The prototype software demonstrates that a generic gamma-ray high-level analysis framework is feasible. CTA analysis in this framework will profit from multi-mission interfaces enabling broad-band spectral analysis of sources from a few tens of keV up to tens of TeV.