The distribution of galaxies as mapped by various Australia, US and European survey teams. In total we have mapped the locations of over 4million galaxies that can be used to study the evolution of mass, energy and structure in the Universe over the past few billion years. Credit: ICRAR/GAMA and ESO
Astronomers studying >200,000 galaxies have measured the energy generated within a large portion of space more precisely than ever before. They confirm that the #energy produced in a section of the Universe today is only ~1/2 what it was 2B yrs ago and find that this fading is occurring across #all #wavelengths from the UV to the far infrared. The Universe is slowly #dying.
The study involves many of the world’s most powerful telescopes, including ESO’s #VISTA and #VST survey telescopes at the Paranal Observatory in Chile. Supporting observations were made by 2 orbiting space telescopes operated by NASA (#GALEX and #WISE) and another belonging to the European Space Agency (#Herschel).
The research is part of the Galaxy And Mass Assembly (#GAMA) project, the largest multi-wavelength survey ever put together. “We used as many space and ground-based telescopes as we could get our hands on to measure the energy output of over 200,000 galaxies across as broad a wavelength range as possible,” says Simon Driver (ICRAR, The University of Western Australia), who heads the large GAMA team. The survey data, includes measurements of the #energy #output of each galaxy at 21 wavelengths. This dataset will help scientists to better understand how different types of #galaxies #orm and #evolve.
All the energy in the Universe was created in the Big Bang, with some portion locked up as mass. Stars shine by #converting #mass back into energy, as described by E=mc2. The GAMA study sets out to map and model all of the energy generated within a large volume of space today and at different times in the past. “While most of the energy sloshing around in the Universe arose in the aftermath of the Big Bang, #additional #energy is constantly being generated by stars as they #fuse elements like #hydrogen and #helium together,” Simon Driver says. “This new energy is either #absorbed by dust as it travels through the host galaxy, or escapes into intergalactic space and travels until it hits something, such as another star, a planet, or, very occasionally, a telescope mirror.”
The fact that the Universe is slowly #fading has been known since the late 1990s, but this work shows that it is happening across all wavelengths from the ultraviolet to the infrared, representing the most comprehensive assessment of the energy output of the nearby Universe. They will #map energy production over the #entire history of the Universe, including the use of #Square #Kilometre #Array, due to be built in Australia and South Africa over the next decade. http://www.eso.org/public/news/eso1533/
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