dark energy

Berkeley Lab’s Dark Energy Spectroscopic Instrument aimed its robotic array of 5,000 fiber-optic “eyes” at the night sky Oct. 22 to capture the first images showing its unique view of galaxy light. It was the first test DESI with its nearly complete complement of components. Fermilab contributed key elements to DESI, including the corrector barrel, hexapod, cage and CCDs. Fermilab also provided the online databases used for data acquisition and the software for the instrument’s robotic positioners.

The Dark Energy Survey has delivered dark energy constraints combining information from four of its primary cosmological probes for the first time, an approach that may help design other experiments into cosmic acceleration.

It took three sky surveys to prepare for a new project that will create the largest 3-D map of the universe’s galaxies and glean new insights about the universe’s accelerating expansion. This Dark Energy Spectroscopic Instrument project will explore this expansion, driven by a mysterious property known as dark energy, in great detail. The surveys, which wrapped up in March, have amassed images of more than 1 billion galaxies and are essential in selecting celestial objects to target with DESI, now under construction in Arizona.

From Cosmos, May 6, 2019: An extensive analysis of four different phenomena within the universe points the way to understanding the nature of dark energy, the Dark Energy Survey reveals.

From APS’s Physics, May 1, 2019: The Dark Energy Survey has combined its analysis of four cosmological observables to constrain the properties of dark energy—paving the way for cosmological surveys that will run in the next decade.

The optical lenses for the Dark Energy Spectroscopic Instrument have seen their first light. Fermilab contributed key components to DESI, including the corrector barrel and its support structures, along with vital software that ensures the instrument’s 5,000 robotic positioners are precisely aligned with their celestial targets.

For The New York Times, Feb. 25, 2019: Axions? Phantom energy? Astrophysicists scramble to patch a hole in the universe, rewriting cosmic history in the process. Fermilab scientist Josh Frieman is quoted in this article.

With the warmth of holiday cheer in the air, some physicists decided to hit the pub after a conference in December 2014 and do what many physicists tend to do after work: keep talking about physics. That evening’s topic of conversation: dark energy particles. The chat would lead to a new line of investigation at the Large Hadron Collider at CERN. Every second, the universe grows a little bigger. Scientists are using the LHC to try to find out why.

From Nature Reviews Physics, Jan. 28, 2019: The Dark Energy Survey completed its six-year-mission to map more than 300 million distant galaxies; however, an equally arduous task — analyzing the acquired 50 terabytes of data with a view to understanding the expansion of the universe — is just beginning.

From APS’s Physics, Jan. 29, 2019: On Jan. 9, a handful of researchers with the Dark Energy Survey — one of the most ambitious attempts to probe the dynamics of the universe’s expansion — headed to the control room of Chile’s Blanco Telescope. For one last time, they opened the white telescope’s dome. From their perch overlooking the red Andean Mountains, they set up for a night of observing the southern sky.