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Suzaku Study Points To Early Cosmic ‘Seeding’

November 1, 2013 Leave a comment

Image Credit: NASA/ISAS/DSS/O. Urban et al., MNRAS

Image Credit: NASA/ISAS/DSS/O. Urban et al., MNRAS

Most of the universe’s heavy elements, including the iron central to life itself, formed early in cosmic history and spread throughout the universe, according to a new study of the Perseus Galaxy Cluster using Japan’s Suzaku satellite.

Between 2009 and 2011, researchers from the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), jointly run by Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory in California, used Suzaku’s unique capabilities to map the distribution of iron throughout the Perseus Galaxy Cluster.

What they found is remarkable: Across the cluster, which spans more than 11 million light-years of space, the concentration of X-ray-emitting iron is essentially uniform in all directions.

“This tells us that the iron — and by extension other heavy elements — already was widely dispersed throughout the universe when the cluster began to form,” said KIPAC astrophysicist Norbert Werner, the study’s lead researcher. “We conclude that any explanation of how this happened demands lead roles for supernova explosions and active black holes.”

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Mystery World Baffles Astronomers

November 1, 2013 Leave a comment

Kepler-78b is a planet that shouldn’t exist. This scorching lava world circles its star every eight and a half hours at a distance of less than one million miles – one of the tightest known orbits. According to current theories of planet formation, it couldn’t have formed so close to its star, nor could it have moved there.

“This planet is a complete mystery,” says astronomer David Latham of the Harvard-Smithsonian Center for Astrophysics (CfA). “We don’t know how it formed or how it got to where it is today. What we do know is that it’s not going to last forever.”

“Kepler-78b is going to end up in the star very soon, astronomically speaking,” agrees CfA astronomer Dimitar Sasselov.

Not only is Kepler-78b a mystery world, it is the first known Earth-sized planet with an Earth-like density. Kepler-78b is about 20 percent larger than the Earth, with a diameter of 9,200 miles, and weighs almost twice as much. As a result it has a density similar to Earth’s, which suggests an Earth-like composition of iron and rock.

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First Results From LUX, The World’s Most Sensitive Dark Matter Detector

November 1, 2013 Leave a comment

After its first run of more than three months, operating a mile underground in the Black Hills of South Dakota, a new experiment named LUX has proven itself the most sensitive dark matter detector in the world.

“LUX is blazing the path to illuminate the nature of dark matter,” says Brown University physicist Rick Gaitskell, co-spokesperson for LUX with physicist Dan McKinsey of Yale University. LUX stands for Large Underground Xenon experiment.

Gaitskell and McKinsey announced the LUX first-run results, on behalf of the collaboration, at a seminar today at the Sanford Underground Research Facility (Sanford Lab) in Lead, S.D. The Sanford Lab is a state-owned facility, and the U.S. Department of Energy (DOE) supports its operation. The LUX scientific collaboration, which is supported by the National Science Foundation and DOE, includes 17 research universities and national laboratories in the United States, the United Kingdom, and Portugal.

Dark matter, so far observed only by its gravitational effects on galaxies and clusters of galaxies, is the predominant form of matter in the universe. Weakly interacting massive particles, or WIMPs – so-called because they rarely interact with ordinary matter except through gravity – are the leading theoretical candidates for dark matter. Theories and results from other experiments suggest that WIMPs could be either “high mass” or “low mass.”

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