Looking 11 billion years back in time to when the universe was very young, astronomers have found that the anatomy of distant galaxies is not that different from galaxies seen in the nearby universe today. The results come from the Hubble Space Telescope Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). The largest project in the history of Hubble, it aims to explore galactic evolution in the early universe, and the very first seeds of cosmic structure at less than 1 billion years after the Big Bang.
Previous studies of this early epoch were inconclusive because they were limited to visible light. Because of the stretching of light by the expansion of the universe the visible light detected in distant galaxies actually maps only the ultraviolet emissions of the galaxies. Because this radiation only comes from regions of active star formation the galaxies appeared to be clumpy and messy, with no resemblance to the galaxy shapes we see around us today. By observing the galaxies in infrared light with Hubble’s Wide Field Camera 3, astronomers could observe how these distant galaxies would appear normally in visible light if their radiation were not stretched to infrared wavelengths by the expanding universe. For more information about this study, visit: http://www.spacetelescope.org/news/heic1315