Tag Archives: dark energy

Calibrating cosmic mile markers

Pasadena, CA — New work from the Carnegie Supernova Project provides the best-yet calibrations for using type Ia supernovae to measure cosmic distances, which has implications for our understanding of how fast the universe is expanding and the role dark energy may play in driving this process. Led by Carnegie astronomer Chris Burns, the team’s findings are published in The Astrophysical Journal.   (more…)

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Accelerating research into dark energy

A quick method for making accurate, virtual universes to help understand the effects of dark matter and dark energy has been developed by UCL and CEFCA scientists. Making up 95% of our universe, these substances have profound effects on the birth and lives of galaxies and stars and yet almost nothing is known about their physical nature. (more…)

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What lit up the universe?

New research from UCL shows we will soon uncover the origin of the ultraviolet light that bathes the cosmos, helping scientists understand how galaxies were built.

The study published in The Astrophysical Journal Letters by UCL cosmologists Dr Andrew Pontzen and Dr Hiranya Peiris (both UCL Physics & Astronomy), together with collaborators at Princeton and Barcelona Universities, shows how forthcoming astronomical surveys will reveal what lit up the cosmos. (more…)

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Stunning images of Andromeda demonstrate the world’s most powerful astronomical camera

Stunning images of the Andromeda Galaxy are among the first to emerge from a new wide-field camera installed on the enormous Subaru Telescope atop the Hawaiian mountain Mauna Kea. The camera, called the Hyper-Suprime Cam (HSC), is the result of an international collaboration between Princeton University astrophysicists and Japanese and Taiwanese scientists.

With this new camera, researchers will be able to conduct a “cosmic census” of hundreds of millions of galaxies in a wide swath of sky in sufficient depth to probe mysteries such as dark matter and dark energy, while searching for baby galaxies in the early universe. The images of the Andromeda Galaxy demonstrate the new camera’s ability to capture images for a large-scale survey that will help scientists understand the evolutionary history and fate of the expanding universe. The camera’s enormous field of view allowed the entire Andromeda Galaxy, which is some 60,000 light years across, to be captured in a single shot. (more…)

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BOSS Quasars Unveil a New Era in the Expansion History of the Universe

Berkeley Lab scientists and their Sloan Digital Sky Survey colleagues use quasars to probe dark energy over 10 billion years in the past

BOSS, the Baryon Oscillation Spectroscopic Survey, is mapping a huge volume of space to measure the role of dark energy in the evolution of the universe. BOSS is the largest program of the third Sloan Digital Sky Survey (SDSS-III) and has just announced the first major result of a new mapping technique, based on the spectra of over 48,000 quasars with redshifts up to 3.5, meaning that light left these active galaxies up to 11.5 billion years in the past.

“No technique for dark energy research has been able to probe this ancient era before, a time when matter was still dense enough for gravity to slow the expansion of the universe, and the influence of dark energy hadn’t yet been felt,” says BOSS principal investigator David Schlegel, an astrophysicist in the Physics Division of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). “In our own time, expansion is accelerating because the universe is dominated by dark energy. How dark energy effected the transition from deceleration to acceleration is one of the most challenging questions in cosmology.” (more…)

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World’s Most Powerful Digital Camera Begins Hunt for Dark Energy

Eight billion years ago, rays of light from distant galaxies began their long journey to Earth. That ancient starlight has now found its way to a mountaintop in Chile, where the newly constructed Dark Energy Camera, the most powerful sky-mapping machine ever created, has captured and recorded it for the first time.

That light may hold within it the answer to one of the biggest mysteries in physics: Why the expansion of the universe is speeding up. (more…)

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