Tag Archives: universe

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…)

How Galaxies Grow Up

By Guest PostOctober 20, 2012Scienceadam block, age, andromeda galaxy, astronomer, benjamin weiner, blue galaxies, california, computer program, computer simulation, deep2, emission line, galaxies, Galaxy, galaxy evolution, galaxy population, galaxy type, gas, grow up, hawaii, internal motion, keck telescopes, lick observatory, light years, m88 galaxy, massive system, Milky Way, mount lemmon, NASA, observational data, random motion, redshift survey, rotation speed, santa cruz, skycenter, spiral disk shape, star forming galaxies, susan kassin, ua, universe, university, velocity

A study of 544 star-forming galaxies shows that disk galaxies like our own Milky Way reached their current state as orderly rotating pinwheels much later than previously thought, long after much of the universe’s star formation had ceased.

Galaxies are in no hurry to grow up, a team of astronomers has discovered. A comprehensive study of hundreds of galaxies observed by the Keck telescopes in Hawaii and NASA’s Hubble Space Telescope has revealed an unexpected pattern of change that extends back 8 billion years, or more than half the age of the universe.

Researchers say the distant blue galaxies they studied are gradually transforming into rotating disk galaxies like our own Milky Way. Until now, it had not been clear how a galaxy’s organization and internal motion change over time, said Benjamin Weiner, assistant astronomer at the UA Steward Observatory and co-author of the paper describing the findings, which are published in The Astrophysical Journal. (more…)

Interstellar Travelers of the Future May be Helped by MU Physicist’s Calculations

By Guest PostOctober 12, 2012Scienceastrophysicists, bill clinton, expansion, future, gravity, heat, human expansion, interstellar travel, light, mechanical explanation, missouri, movement, newtonian law, photon, physics, pioneer spacecraft, puzzle, radio wave, research project, researcher, sergei kopeikin, Space, spaceship symposium, star system, theory, time, universe, university

University of Missouri’s Sergei Kopeikin may have solved the Pioneer anomaly

COLUMBIA, Mo. – Former President Bill Clinton recently expressed his support for interstellar travel at the 100 Year Spaceship Symposium, an international event advocating for human expansion into other star systems. Interstellar travel will depend upon extremely precise measurements of every factor involved in the mission. The knowledge of those factors may be improved by the solution a University of Missouri researcher found to a puzzle that has stumped astrophysicists for decades.

“The Pioneer spacecraft, two probes launched into space in the early 70s, seemed to violate the Newtonian law of gravity by decelerating anomalously as they traveled, but there was nothing in physics to explain why this happened,” said Sergei Kopeikin, professor of physics and astronomy in MU’s College of Arts and Science. “My study suggests that this so-called Pioneer anomaly was not anything strange. The confusion can be explained by the effect of the expansion of the universe on the movement of photons that make up light and radio waves.” (more…)

A Clock that Will Last Forever

By Guest PostSeptember 24, 2012Science3d solid, 4d crystal, berkeley lab, clock, coulomb repulsion, crystal, crystallization, electric field, electrical charge, energy state, entanglement, entropy, forever, frank wilczek, haitao quan, heat death, ice, ion trap, luming duan, particle, peng zhang, periodic structure, phenomena, physics, quantum, quantum world, ring crystal, salt, snowflake, Space, spatial, structure, thermodynamic equilibrium, time, tongcang li, universe, wow factor, xiang zhang, xiaobo yin, zhang qi yin, zhe xuan gong

Berkeley Lab Researchers Propose a Way to Build the First Space-Time Crystal

Imagine a clock that will keep perfect time forever, even after the heat-death of the universe. This is the “wow” factor behind a device known as a “space-time crystal,” a four-dimensional crystal that has periodic structure in time as well as space. However, there are also practical and important scientific reasons for constructing a space-time crystal. With such a 4D crystal, scientists would have a new and more effective means by which to study how complex physical properties and behaviors emerge from the collective interactions of large numbers of individual particles, the so-called many-body problem of physics. A space-time crystal could also be used to study phenomena in the quantum world, such as entanglement, in which an action on one particle impacts another particle even if the two particles are separated by vast distances.

A space-time crystal, however, has only existed as a concept in the minds of theoretical scientists with no serious idea as to how to actually build one – until now. An international team of scientists led by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has proposed the experimental design of a space-time crystal based on an electric-field ion trap and the Coulomb repulsion of particles that carry the same electrical charge. (more…)

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

By Guest PostSeptember 22, 2012Scienceancient starlight, atmospheric condition, billion years, brazil, brenna flaugher, camera, cerro tololo, Chicago, Chile, chilean andes, chris smith, dark energy, des, distant galaxy, earth, expansion, fermilab, galaxy cluster, Germany, gravitational lensing, inter american, james siegrist, kavli institute, mystery, ngc 1365, noao, observatory, physics, southern sky, spain, spiral galaxy, switzerland, telescope, united kingdom, universe, university, victor m blanco

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…)

First Stars, Galaxies Formed more Rapidly than Expected

By Guest PostSeptember 9, 2012Scienceanalysis, anisotropy probe, Antarctica, astronomer, background, Berkeley, california, christian reichardt, cmb, cosmic microwave, cosmological evolution, data, earth axis, electron, Epoch, Galaxy, geographic, herschel satellite, high resolution, hydrogen atom, image, john carlstrom, kavli foundation, microwave, millimeter wavelength, national, neutral, neutral gas, oliver zahn, period, plasma, polar plateau, proton, radiation, reionization, s chandrasekhar, science foundation, south pole, star, telescope, ultraviolet light, universe, university, wilkinson

Analysis of data from the National Science Foundation’s South Pole Telescope, for the first time, more precisely defines the period of cosmological evolution when the first stars and galaxies formed and gradually illuminated the universe. The data indicate that this period, called the epoch of reionization, was shorter than theorists speculated — and that it ended early.

“We find that the epoch of reionization lasted less than 500 million years and began when the universe was at least 250 million years old,” said Oliver Zahn, a postdoctoral fellow at the Berkeley Center for Cosmological Physics at the University of California, Berkeley, who led the study. “Before this measurement, scientists believed that reionization lasted 750 million years or longer, and had no evidence as to when reionization began.” (more…)

Supernovae of the Same Brightness, Cut From Vastly Different Cosmic Cloth

By Guest PostSeptember 1, 2012Sciencealex filippenko, andy howell, ben dilday, berkeley lab, constellation lynx, cosmic distance, discovery, esnet, exploding stars, hawaii, jeffrey silverman, joshua bloom, keck telescope, las cumbres observatory, lcogt, lick observatory, light year, milky way galaxy, NASA, origin, palomar transient factory, peter nugent, progenitor systems, ptf, ptf 11kx, red giant star, rs ophiuchi, samuel oschin, shane telescope, sky, sn 2011fe, southern california, spectroscopy, supernova, target of opportunity, telescope, too, type 1a, universe, university of california

Berkeley Lab researchers make historic observation of rare Type 1a Supernova

Exploding stars called Type 1a supernova are ideal for measuring cosmic distance because they are bright enough to spot across the Universe and have relatively the same luminosity everywhere. Although astronomers have many theories about the kinds of star systems involved in these explosions (or progenitor systems), no one has ever directly observed one—until now.

In the August 24 issue of Science, the multi-institutional Palomar Transient Factory (PTF) team presents the first-ever direct observations of a Type 1a supernova progenitor system. Astronomers have collected evidence indicating that the progenitor system of a Type 1a supernova, called PTF 11kx, contains a red giant star. They also show that the system previously underwent at least one much smaller nova eruption before it ended its life in a destructive supernova. The system is located 600 million light years away in the constellation Lynx. (more…)

Astronomers Using the Hubble Space Telescope Report the Earliest Spiral Galaxy Ever Seen

By Guest PostJuly 19, 2012Sciencealice shapley, astronomer, big bang, bx442, charles steidel, david law, dawn erb, early universe, elliptical galaxy, hawaii, Hubble Space Telescope, james larkin, journal nature, keck observatory, mauna kea volcano, Milky Way, naveen reddy, osiris spectrograph, spiral galaxy, universe

Astronomers have witnessed for the first time a spiral galaxy in the early universe, billions of years before many other spiral galaxies formed. In findings reported July 19 in the journal Nature, the astronomers said they discovered it while using the Hubble Space Telescope to take pictures of about 300 very distant galaxies in the early universe and to study their properties. This distant spiral galaxy is being observed as it existed roughly three billion years after the Big Bang, and light from this part of the universe has been traveling to Earth for about 10.7 billion years.

“As you go back in time to the early universe, galaxies look really strange, clumpy and irregular, not symmetric,” said Alice Shapley, a UCLA associate professor of physics and astronomy, and co-author of the study. “The vast majority of old galaxies look like train wrecks. Our first thought was, why is this one so different, and so beautiful?” (more…)