Astronomer Alan Dressler Sets Off on the Trail of the First Galaxies in the Universe

摘要

What did the universe look like in its toddler years? To find out, astronomer Atari Dressier of the Carnegie Institution of Washington and his team are training some of the world's largest telescopes on a small swath of sky in the constellation Sextans. Their aim is to detect "Lyman-alpha emitters," distant gas clouds enclosing primordial stars. The blobs hail from a crucial moment when those first stars flooded the cosmos with energy, setting off a chain of events that led to the formation of modern galaxies. Last year Dressler's colleague Masami Ouchi found the king of the blobs: Nicknamed Himiko, it is 55,000 light-years in diameter, making it the largest object ever seen so early in the universe. Dressier spoke with DISCOVER about what it all means.