The dark burst 010214 with BeppoSAX Possible variable absorption and jet X-ray emission

We report on the prompt and afterglow emission observations of the dark burst GRB010214 with BeppoSAX. The prompt emission shows possible evidence of variable absorption from NH = 3.0+5.1-2.0 x 1023 cm-2 in the first 6 s of the event to a value consistent with the Galactic column density (NHG = 2.66x 1020 cm-2) in the GRB direction. An X-ray afterglow emission in the 2-10 keV energy band was detected with BeppoSAX, but an analogue search at lower wavelengths (optical, IR and radio) was unsuccessful. The X-ray afterglow spectrum is consistent with a power-law with Galactic absorption. The light curve shows a complex decay, if the tail of the prompt emission is assumed as the onset of the afterglow: if the origin of the afterglow is coincident with the GRB onset, a bump before ~ 3*E4 s is inferred, while if the afterglow is assumed to start later, a steepening of the power-law light curve at t ~ 3*E4 s is deduced. We discuss these results in the light of the current models of afterglows and the possible origin of the GRB darkness. Finally, we tentatively derive an estimate of the burst redshift.