The first billion years of cosmic history represents the final frontier in assembling a coherent physical picture of early galaxy formation, and a remarkable progress in this area has been made in the last few years. We have carried out a detailed analysis of a gravitationally lensed galaxy A2744_YD4 at z = 8.38 behind the massive galaxy cluster Abell 2744. The photometric redshift of about 8, estimated from HST, VLT and Spitzer data, was confirmed by the detection of the Ly_alpha line at a redshift of z=8.38 in a deep VLT X-SHOOTER spectrum. The follow-up observations with the Atacama Large
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