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Clocking an Accelerating Universe: First Results from BOSS

By Guest PostApril 4, 2012Scienceaccelerate, adam riess, apache point observatory, bao, baryon acoustic oscillation, berkeley lab, beth reid, big bang, brian schmidt, cmb, cosmic microwave background, dan long, dark energy, david schlegel, density peak, einstein, eric huff, euclidean universe, Galaxy, george smoot, gravitational attraction, gravity, high z supernova, hubble, martin white, megaparsecs, Milky Way, new mexico, nobel prize, phenomenon, redshifts, saul perlmutter, scp, sdss, sloan telescope, spectrograph, statistical analysis, universe, zosia rostomian

Berkeley Lab scientists are the leaders of BOSS, the Baryon Oscillation Spectroscopic Survey. They and their colleagues in the third Sloan Digital Sky Survey have announced the most precise measurements ever made of the era when dark energy turned on.

Some six billion light years distant, almost halfway from now back to the big bang, the universe was undergoing an elemental change. Held back until then by the mutual gravitational attraction of all the matter it contained, the universe had been expanding ever more slowly. Then, as matter spread out and its density decreased, dark energy took over and expansion began to accelerate.

Today BOSS, the Baryon Oscillation Spectroscopic Survey, the largest component of the third Sloan Digital Sky Survey (SDSS-III), announced the most accurate measurement yet of the distance scale of the universe during the era when dark energy turned on. (more…)

Just Four Percent of Galaxies Have Neighbors Like the Milky Way

By Guest PostMay 26, 2011Scienceanalyses of data, big bang, cdm, cold dark matter theory, computer model, formation of our galaxy, Galaxy, luminosity, magellanic clouds, Milky Way, nigel sharp, optical sky, risa wechsler, sdss, stanford university, universe

*Our home galaxy belongs to a rare subset among the billions that populate the cosmos*

How unique is the Milky Way?

To find out, a group of researchers led by Stanford University astrophysicist Risa Wechsler compared the Milky Way to similar galaxies and found that just four percent are like the galaxy Earth calls home. (more…)

Measuring the Distant Universe in 3-D

By Guest PostMay 7, 2011Science3 d map, absorption, anže slosar, apache point observatory, bao, baryon acoustic oscillation, baryon oscillation, baryon oscillation spectroscopic survey, berkeley lab, bill carithers, BOSS, centers of galaxies, dark energy, david schlegel, james rich, lyman alpha forest, map intergalactic hydrogen gas, new mexico, of light years, precision tool, quasars, red galaxies, redshift, sdss, sloan digital sky survey, sloan telescope, spectrum, supermassive black holes, universe, wiggly structure

*Berkeley Lab-led BOSS proves it can do the job with quasars*

The biggest 3-D map of the distant universe ever made, using light from 14,000 quasars — supermassive black holes at the centers of galaxies many billions of light years away — has been constructed by scientists with the third Sloan Digital Sky Survey (SDSS-III).

The map is the first major result from the Baryon Oscillation Spectroscopic Survey (BOSS), SDSS-III’s largest survey, whose principal investigator is David Schlegel of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). The huge new map was presented at the April meeting of the American Physical Society in Anaheim, CA, by Anže Slosar of Brookhaven National Laboratory. (more…)

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Clocking an Accelerating Universe: First Results from BOSS

Just Four Percent of Galaxies Have Neighbors Like the Milky Way

Measuring the Distant Universe in 3-D