16th Annual Astrophysics Conference, Washington, Kiribati, 29 Kasım - 02 Aralık 2005, cilt.836, ss.428-429
We present a catalog of X-ray afterglows observed by BeppoSAX, XMM-Newton and Chandra. We put constraints on the burst environment and geometry. We observe a temporal evolution of these constraints, by comparing the fast BeppoSAX and XMM-Newton follow-up and the late Chandra observations. We do not observe strong discrepancies when comparing the BeppoSAX sample to the XMM-Newton one and to some SWIFT bursts selected to be observed at late time.