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

By Guest PostNovember 21, 2012Scienceacceleration, analytic techniques, ancient universe, andreu font ribera, apache point observatory, bao, baryon, baryon acoustic oscillations, berkeley lab, bigboss, bill carithers, BOSS, clouds, cosmology, dark energy, dark matter, data sets, david schlegel, deceleration, density variation, digital sky survey, early universe, evolution, expanse of sky, expansion, gas clouds, gas density, gravity, hydrogen absorption lines, intergalactic gas, lyman alpha forest, mocks, new mexico, nicholas ross, oscillation, patrick mcdonald, quasars, riemann linux cluster, sdss, sloan, Space, spectra, spectroscopic, survey, universe, volume

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…)

Star Explosion Leaves Behind a Rose

By Guest PostDecember 11, 2011Scienceancient supernova, bright star, cosmic cannonball, dense object, dust, earth, explosion, gas clouds, massive star, modern astronomers, NASA, neutron star, puppis a, red rose, shock waves, Space, supernova, universe, vela supernova, wide field infrared survey explorer, wise

About 3,700 years ago, people on Earth would have seen a brand-new bright star in the sky. It slowly dimmed out of sight and was eventually forgotten, until modern astronomers later found its remains, called Puppis A. In this new image from NASA’s Wide-field Infrared Survey Explorer (WISE), Puppis A looks less like the remains of a supernova explosion and more like a red rose.

Puppis A (pronounced PUP-pis) was formed when a massive star ended its life in a supernova, the most brilliant and powerful form of an explosion in the known universe. The expanding shock waves from that explosion are heating up the dust and gas clouds surrounding the supernova, causing them to glow and appear red in this infrared view. While much of the material from that original star was violently thrown out into space, some of it remained in an incredibly dense object called a neutron star. This particular neutron star (too faint to be seen in this image) is moving inexplicably fast: over 3 million miles per hour! Astronomers are perplexed over its absurd speed, and have nicknamed the object the “Cosmic Cannonball.” (more…)

Astronomers Find Bounty of Failed Stars

By Guest PostOctober 14, 2011Sciencealeks scholz, astronomical oddballs, brown dwarfs, Chile, dublin institute of advanced studies, eth zurich, failed stars, garching, gas clouds, Germany, giant planets, hawaii, ireland, jupiter, koraljka muzic, mariangela bonavita, motohide tamura, ngc 1333, optical and infrared wavelengths, planets, ray jayawardhana, rho ophiuchi star, sonyc, stars, subaru telescope, substellar objects in nearby young clusters, switzerland, university of toronto, very large telescope, vincent geers, vlt

*One youngster only six times heftier than Jupiter*

TORONTO, ON – A University of Toronto-led team of astronomers has discovered over two dozen new free-floating brown dwarfs, including a lightweight youngster only about six times heftier than Jupiter, that reside in two young star clusters. What’s more, one cluster contains a surprising surplus of them, harbouring half as many of these astronomical oddballs as normal stars.

“Our findings suggest once again that objects not much bigger than Jupiter could form the same way as stars do. In other words, nature appears to have more than one trick up its sleeve for producing planetary mass objects,” says Professor Ray Jayawardhana, Canada Research Chair in Observational Astrophysics at the University of Toronto and leader of the international team that made the discovery. (more…)

Tag Archives: gas clouds

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

Star Explosion Leaves Behind a Rose

Astronomers Find Bounty of Failed Stars