The X-ray afterglow of GRB 980519

Over a total of 20 gamma-ray bursts localized with arcmin accuracies, GRB 9 80519 represents the 13th detected by the BeppoSAX Wide Field Cameras (WFCs ). An X-ray TOO observation performed by the BeppoSAX Narrow Field Instrume nts (NFIs), starting about 9.5 hours after the high energy event, revealed X-ray afterglow emission in the 0.1-10 keV energy range. The flux decay was particularly fast with a power-law index of similar or equal to 1.8. This is the fastest decay so far measured. Signs of bursting activity are eviden t. The power-law spectral index of 2.8(-0.5)(+0.6) is quite soft but not un ique among GRB afterglows. VRcIc optical emission was detected as soon as 8 hours after the GRB and th e power-law flux decay in all these bands were all consistent with delta si milar or equal to 2.0. As for the X-ray, this is the fastest of all the 9 o ptically identified afterglows but GRB 980326. A candidate host galaxy with magnitude R-c = 26 has been reported and variable radio emission detected.