Source direction

In chapter 3 we have discussed the dependency of GRBM detectors responses both in the GRBM/AC ratemeters and the energy spectra on incoming photons direction. The position of a celestial source of known coordinates with respect to each LS can be easily reconstructed utilizing the satellite attitude data, which are part of the final FOT (section 1.1.3) and are expressed in terms of the $\theta$ and $\phi$ angles defined in section 2.4.4. This is the case, for instance, of Crab nebula or SGR1900+14 (chapter 5) observations, sources having well known celestial coordinates.
Because, as discussed in chapter 6, the GRBM source localizing capabilities are still under investigation basing on the work on the response functions described in this Thesis ([Preger et al. 1999]), in the case of GRBs it is possible to analyze only those events whose positions have been determined by the WFC (with few arcmin accuracy) or other missions, like BATSE (some degrees positioning accuracy for strong GRBs).

Nevertheless, for what concerns this Thesis work, we have applied GRBM response functions and data analysis techniques to the study of GRBs simultaneously detected by the GRBM and WFC and thus having a well known position in the sky and directions very close to LS1 or LS3 axis. As discussed in chapter 3, for these directions we have a satisfactory knowledge of the detectors energy response functions both for ratemeters and 240 channels spectra.