June 4, 2014
Most Colorful View Of The Universe Captured By Hubble Space Telescope
April Flowers for redOrbit.com - Your Universe Online
In a new study called the Ultraviolet Coverage of the Hubble Ultra Deep Field (UVUDF) project, the most comprehensive and colorful picture of the evolving universe has been captured by astronomers using the Hubble Space Telescope.
Prior to the UVUDF study, astronomers knew a great deal about star formation that occurred in nearby galaxies, thanks to UV telescopes such as NASA's GALEX observatory. The astronomers were also able to study star birth in the most distant galaxies using Hubble's near-infrared and visible capabilities. Due to the vast amount of time it takes for the light from these galaxies to reach the Earth, these galaxies are seen in their most primitive stages.
There is a distinct lack of knowledge concerning star formation in the middle distance, however, between 5 and 10 billion light-years from Earth. It is during this time period when most of the stars in the Universe were born. Because they emit light in the ultraviolet, the hottest, most massive and youngest stars have largely been ignored as subjects of direct observation. This has left an enormous gap in our understanding of the cosmic timeline.
"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. "The addition of the ultraviolet fills in this missing range."
Access to this portion of the timeline has become available since the addition of ultraviolet data to the Hubble Ultra Deep Field using Hubble's Wide Field Camera 3. The new addition allowed the scientists direct observation of regions of unobscured star formation. Using the new wavelengths to obtain data, the research team was able to look at which galaxies had stars forming and where the stars formed. Such information adds to our knowledge of how galaxies like our own Milky Way grew in size from small collections of very hot stars to the massive structures we observe today.
[ Watch the Video: Hubble’s Colorful View Of The Universe ]
The sky region illustrated in the new image released by the Hubble astronomers has been studied before in a series of visible and near-infrared exposures taken as part of the Hubble Ultra Deep Field (HUDF) project from 2003 to 2009. These exposures reveal a small region of the sky in the southern-hemisphere constellation Fornax. The new ultraviolet wavelengths, combined with the near-infrared and visible wavelengths, reveals the total spectrum of colors available to the Hubble. This allowed the new image, made from 841 orbits of viewing time, to capture nearly 10,000 galaxies. The light captured extends back to within a few hundred million years of the Big Bang.
Only a space-based telescope, such as the Hubble, could take such an image because the Earth's atmosphere filters out most ultraviolet light. Hubble's ultraviolet surveys are critical for the planning for the James Webb Space Telescope, which is currently under development as a joint project between NASA, the European Space Agency, and the Canadian Space Agency. Currently, the 24-year-old Hubble spacecraft is the only space-based telescope capable of obtaining ultraviolet data that will be necessary to combine with infrared data from JWST.
Team member Dr. Rogier Windhorst of Arizona State University said, "Hubble provides an invaluable ultraviolet light dataset that researchers will need to combine with infrared data from Webb. This is the first really deep ultraviolet image to show the power of that combination."