A study of the prompt and afterglow emission of the short GRB 061201

Context Our knowledge of the intrinsic properties of short duration Gamma-Ray Bursts has relied, so far, only upon a few cases for which the estimate of the distance and an extended, multiwavelength monitoring of the afterglow have been obtained. <BR />Aims We carried out multiwavelength observations of the short GRB 061201 aimed at estimating its distance and studying its properties. <BR />Methods We performed a spectral and timing analysis of the prompt and afterglow emission and discuss the results in the context of the standard fireball model. <BR />Results A clear temporal break was observed in the X-ray light curve about 40 min after the burst trigger. We find that the spectral and timing behaviour of the X-ray afterglow is consistent with a jet origin of the observed break, although the optical data can not definitively confirm this and other scenarios are possible. No underlying host galaxy down to R ~ 26 mag was found after fading of the optical afterglow. Thus, no secure redshift could be measured for this burst. The nearest galaxy is at z = 0.111 and shows evidence of star formation activity. We discuss the association of GRB 061201 with this galaxy and with the ACO S 995 galaxy cluster, from which the source is at an angular distance of 17'' and 8.5', respectively. We also test the association with a possible undetected, positionally consistent galaxy at z ~ 1. In all these cases, in the jet interpretation, we find a jet opening angle of 1-2 degrees. The results reported in this paper are partially based on observations carried out at ESO telescopes under program 078.D-0809.