Discovery of the Most Distant Galaxy in the Cosmic Dawn

The Subaru Telescope has repeatedly broken a world record for the most distant galaxy ever observed by humankind. One such example is a discovery of SXDF-NB1006-2 at a distance of 12.91 billion light years from the Earth (or at a redshift of 7.215). Astronomers verified that the proportion of neutral hydrogen gas in the 750-million-year-old early universe was higher than it is today. This is consistent with the view of the universe becoming more neutral and opaque to light when we look further in distance ‑ and therefore, earlier in time. These findings help us understand the nature of the early universe during the “cosmic dawn”, when the light of ancient celestial objects and structures appeared from obscurity.