Optical Line Emission from $z$ ∼ 6.8 Sources with Deep Constraints on Ly$\alpha$ Visibility

K.C. acknowledges funding from the European Research Council through the award of the Consolidator Grant ID 681627-BUILDUP. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n 312725. This work is based on data obtained with ESO Programmes 084.A-0951, 085.A-0844, 086.A-0968, 088.A-1013, 088.A-0192, and 190.A-0685.