NEW YORK: A team of astronomers has taken the measure of the most distant galaxy yet. It shines with unexpected brightness – an observation that could yield new insights into a period when the universe was emerging from its “dark ages.”
The results come from one of two studies unveiled this week that each provide fresh revelations about the formation and evolution of galaxies early in the universe’s history and their impact on the evolution of the cosmos.
The dark ages lasted for some 400 million years after the universe cooled following the Big Bang. During this period, a fog of neutral hydrogen gas permeated the cosmos between infant galaxies. Over time, however, the collective radiation from the enormous, hot stars that filled these growing galaxies slowly burned off the fog by ionizing the hydrogen. The gradual clearing allowed radiation to traverse the cosmos.
NASA’s Hubble and Spitzer Space Telescopes initially spotted the galaxy. Their data hinted that it was filled with what some team members termed unusually hot stars. Using the 10-meter Keck telescope in Hawaii, the research team detected the galaxy, designated EGSY8p7, via ultraviolet light coming from its young, massive, hydrogen-burning stars.
