Thanks to the data collected by the Hubble Space Telescope, astronomers have put together the most comprehensive, and strikingly colorful, image yet of the Universe. The composite picture, called Hubble Ultra Deep Field 2014, combines separate images taken over a period of almost a decade using Hubble’s Advanced Camera for Surveys and Wide Field Camera 3.
Scientists have learnt a lot about star formation over the years using data collected from powerful instruments such as Hubble, but pieces were missing from the puzzle. Information had been gathered from nearby galaxies using facilities such as NASA’s Galaxy Evolution Explorer observatory and also the most distant galaxies using Hubble’s near-infrared and visible capability. Due to the significant amount of time that it takes light to travel to us from these distant galaxies, we observe them in their early, primitive stages.
But what about the period in between? This information is pivotal to comprehending star formation, yet scientists were lacking this data. In particular, there was somewhat of a black box between 5 and 10 billion light-years away from Earth, which is actually when the majority of the stars in the Universe were formed.
This gap in information was due to the fact that the youngest, biggest stars emit UV light and Hubble was only gathering data using near-infrared and visible light. In order to fill in the blanks, UV data was added to the Hubble Ultra Deep Field (HUDF) using Hubble’s Wide Field Camera 3.
“The lack of information from ultraviolet light made studying galaxies in the HUDF like trying to understand the history of families without knowing about the grade-school children,” said principal investigator Harry Teplitz of Caltech.
This addition of wavelengths allowed scientists to deduce which galaxies were forming stars and where these events were occurring in primitive galaxies. This data can then be used to extrapolate information on how other galaxies, including our own Milky Way, might evolve from small, primitive gatherings of stars to the large, complex systems we see now.
The impressive composite image produced from the information contains around 10,000 galaxies and extends back to just a few million years after the Big Bang. And isn’t it beautiful?
Image credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst Arizona State University and Z. Levay (STScI)?