Cross-Check with Other Catalogs

As already described in the previous chapter, the off-line quest made use of some catalogs derived from other contemporary missions with BeppoSAX, in order to discover which bursts have been detected by the GRBM in common with other detectors. This cross-check has turned out to be of key importance for several reasons: first of all, lots of faint bursts that triggered the off-line quest were classified as GRBs afterwards, thanks to the common detection, as they could not be interpreted as spikes produced by particles' interactions; second, some useful informations, such as direction, have been assumed a priori in order to test the localization technique based on the GRBM data, and to study the GRBM efficiency as a function of the GRBM local direction. Finally, especially for the BATSE non-triggered bursts catalogs compiled by Kommers ([Kommers et al., 1999]) and by Stern et al. ([Stern et al., 2000b]), to some extent, all the common GRBs with the GRBM catalog are definitely confirmed as GRBs.

Below, the different subsets of GRBs in common with other catalogs are reported; a remarkable attention has been paid to the WFC-IPN (et al.) bursts, because these bursts show the best accuracy as for the direction estimates; hereafter, these accurate GRBs are called ``well localized bursts''. Then, the BATSE 4B catalog follows, whose systematic error for the burst locations amounts to $\sim 1.6\rm ^{\circ}$ ([Paciesas et al., 1999]); eventually, the non-triggered BATSE catalogs, which are affected by the largest uncertainties, owing the great number of faint bursts, are taken into account.

All the bursts that have been detected by the GRBM and other two experiments, for example WFC and BATSE (like the famous GRB990123), have been taken into account only in the set, that yielded the best localization; e.g. GRB990123, observed by BATSE, but also by the WFC.