Spectroscopic confirmation of a gravitationally lensed Lyman-break galaxy at <i>z</i>[C <scp>ii</scp>] = 6.827 using NOEMA

We present the spectroscopic confirmation of brightest known gravitationally lensed Lyman break galaxy in Epoch Reionisation, A1703-zD1, through detection [C II] at a redshift z = 6.8269 +/- 0.0004. This source was selected behind strong lensing cluster Abell 1703, with an intrinsic L$_{UV}$ ~ L$^*$$_{z=7}$ luminosity and very blue Spitzer/IRAC [3.6]-[4.5] colour, implying high equivalent width line emission [O III]+H$\beta$. is reliably detected 6.1$\sigma$ co-spatial rest-frame UV counterpart, showing similar spatial extent. Correcting for magnification, A1703-zD1 broadly consistent local L$_{[CII]}$ - SFR relation. find clear velocity gradient 103 22 km/s across which possibly indicates rotation or ongoing merger. furthermore spectral scans no above 4.6$\sigma$ two unlensed galaxies EGS-CANDELS field 6.6 6.9. first time that NOEMA has been successfully used to observe 'normal' star-forming > 6, our results demonstrate its capability complement ALMA confirming Reionisation.