Wolf-Rayet stars, more than 20 times as massive as the Sun and at least five times as hot, are relatively rare and often obscured. Scientists don’t know much about how they form, live and die.
The Baryon Oscillation Spectroscopic Survey (BOSS) pioneered the use of quasars to chart the universe’s expansion and investigate the properties of dark energy through studies of large-scale structure. New techniques of analysis led by Berkeley Lab scientists, combined with other new BOSS quasar measures of the young universe’s structure, have produced the most precise measurement of expansion since galaxies formed.
In 1996 Uros Seljak was a postdoc at Harvard, contemplating ways to extract information from the cosmic microwave background (CMB). The distribution of anisotropies, slight temperature differences, in the CMB had much to say about the large-scale structure of the universe. If it were also possible to detect the polarization of the CMB itself, however,
The Baryon Oscillation Spectroscopic Survey (BOSS), the largest component of the third Sloan Digital Sky Survey, has measured the clustering of nearly 1.3 million galaxies spectroscopically to determine the “standard ruler” of the universe’s large-scale structure to within one percent. This is the most precise such measurement ever made and is likely to establish the standard for years to come.
New results from IceCube, the neutrino observatory buried at the South Pole, may show the way to locating and identifying cosmic accelerators in our galaxy that are 40 million times more powerful than the Large Hadron Collider at CERN.
Berkeley Lab researchers take the furthest look back through time yet – 100 years to 300,000 years after the Big Bang – and find tantalizing new hints of clues as to what might have happened.
Type Ia supernovae are indispensable milestones for measuring the expansion of the universe. With definitive measures of Supernova 2011fe, the same “Backyard Supernova” that thrilled amateur and professional astronomers alike in the summer of 2011, the Nearby Supernova Factory led by Lawrence Berkeley National Laboratory demonstrates that this unusually close-by Type Ia is such a perfect example of its kind that future Type Ia’s – and models meant to explain their physics – must be measured against it.
The Planck collaboration has released its first cosmological results, based on trillions of measurements of the cosmic microwave background. The results owe much to Berkeley Lab’s National Energy Research Scientific Computing Center (NERSC), including tens of millions of hours of massively parallel processing, plus the expertise of physicists and computational scientists in the Computational Cosmology Center (C3) who generated a quarter of a million simulated maps of the Planck sky, essential to the analysis.
A very special clock that can measure time on the basis of the mass of a single atomic or even subatomic particle holds promise not only for ultraprecise measurements of mass and time, but also for such exotic applications as testing Einstein’s general theory of relativity, or the effects of gravity on antimatter. “We have
In 2004 the Supernova Cosmology Project used the Hubble Space Telescope to find a tantalizing supernova that appeared to be almost 10 billion light-years distant. But Berkeley Lab scientists had to wait until a new camera was installed on the Hubble years later before they could confirm the candidate’s identity and redshift as a Type Ia “standard candle.” The spectrum and light curve of supernova SCP-0401 are now known with clarity; it is the supernova furthest back in time that can be used for precise measurements of the expansion history of the universe.