A new high-redshift Lyα emitter:: Possible superwind galaxy at z=5.69

During the course of our deep optical imaging survey for Lyalpha emitters at in the field around the z approximate to 5.7 z = 5.74 quasar SDSSp J104433.04-012502.2, we found a candidate strong emission line source. Follow-up z p 5.74 optical spectroscopy shows that the emission-line profile of this object is asymmetric, showing excess red wing emission. These properties are consistent with an identification of Lyalpha emission at a redshift of z = 5.687 +/- 0.002. The observed broad line width (Deltav(FWHM) similar or equal to 340 km s(-1)) and excess red wing emission also suggest that this object hosts a galactic superwind.