Archive

Posts Tagged ‘evolution of the universe’

How A New Telescope Will Measure The Expansion Of The Universe


For the past several years, scientists at the U.S. Department of Energy’s Lawrence Berkeley National Lab (Berkeley Lab) have been planning the construction of and developing technologies for a very special instrument that will create the most extensive three-dimensional map of the universe to date. Called DESI for Dark Energy Spectroscopic Instrument, this project will trace the growth history of the universe rather like the way you might track your child’s height with pencil marks climbing up a doorframe. But DESI will start from the present and work back into the past.

DESI will make a full 3D map pinpointing galaxies’ locations across the universe. The map, unprecedented in its size and scope, will allow scientists to test theories of dark energy, the mysterious force that appears to cause the accelerating expansion and stretching of the universe first discovered in observations of supernovae by groups led by Saul Perlmutter at Berkeley Lab and by Brian Schmidt, now at Australian National University, and Adam Riess, now at Johns Hopkins University.

Link To Full Story

Advertisements

One-Percent Measure Of The Universe Constrains Dark Energy

January 10, 2014 Leave a comment

At the January AAS meeting, researchers from the Baryon Oscillation Spectroscopic Survey (BOSS) announced that they have measured the distance to galaxies more than six billion light years away to an accuracy of one percent. Together with information on the rate at which the Universe was expanding, these measurements allow the scientists at the Max Planck Institute for Extraterrestrial Physics to place powerful constraints on the properties of the mysterious Dark Energy. This component is thought to be responsible for the current accelerated expansion of the Universe.

The new distance measurements were presented at the meeting of the American Astronomical Society by Harvard University astronomer Daniel Eisenstein, the director of SDSS-III. They are detailed in a series of articles submitted by the BOSS collaboration last month and available online. “Determining distance is a fundamental challenge of observational astronomy,” said Eisenstein. “You see something in the sky — how far away is it?”

Link To Full Story

WMAP Team Releases Final Results, Based On Nine Years Of Observations

January 4, 2013 Leave a comment

Since its launch in 2001, the Wilkinson Microwave Anisotropy Probe (WMAP) space mission has revolutionized our view of the universe, establishing a cosmological model that explains a widely diverse collection of astronomical observations. Led by Johns Hopkins astrophysicist Charles L. Bennett, the WMAP science team has determined, to a high degree of accuracy and precision, not only the age of the universe, but also the density of atoms; the density of all other non-atomic matter; the epoch when the first stars started to shine; the “lumpiness” of the universe, and how that “lumpiness” depends on scale size.

In short, when used alone (with no other measurements), WMAP observations have made our knowledge of those six parameters above about 68,000 times more precise, thereby converting cosmology from a field of often wild speculation to a precision science.

Now, two years after the probe “retired,” Bennett and the WMAP science team are releasing its final results, based on a full nine years of observations.

“It is almost miraculous, says Bennett, Alumni Centennial Professor of Physics and Astronomy and Johns Hopkins Gilman Scholar at the Johns Hopkins University’s Krieger School of Arts and Sciences. “The universe encoded its autobiography in the microwave patterns we observe across the whole sky. When we decoded it, the universe revealed its history and contents. It is stunning to see everything fall into place.”

Full Story, Results and Links: http://releases.jhu.edu/2012/12/21/wmap-team-releases-final-results-based-on-nine-years-of-observations/

First Results from e-MERLIN’s Survey of Hubble Deep Field

March 27, 2012 Leave a comment

A team of astronomers at Jodrell Bank Observatory have begun the deepest ever high-resolution radio imaging of the region around the Hubble Deep Field (HDF), the images originally captured by the Hubble Space Telescope (HST) in the mid 1990s. The HDF led to the discovery of numerous galaxies billions of light years distant and provided direct visual evidence of the evolution of the Universe. First results from the new imaging, which uses observations from the UK’s newly upgraded e-MERLIN radio telescope array together with the EVLA radio array based in New Mexico, show galaxies some 7 billion light years away in unprecedented detail. Graduate student Nick Wrigley will present the new results at the National Astronomy Meeting in Manchester on 27 March 2012.

e-MERLIN is an array of radio telescopes distributed across the United Kingdom connected together by optical fibres. Data from each telescope is sent across this network to Jodrell Bank where a device known as a ‘correlator’ processes them into a single image. This technique, known as interferometry, simulates a single radio telescope hundreds of kilometres across and produces exceptionally sharp images of astronomical objects.

Full Story: http://www.jodrellbank.manchester.ac.uk/meetings/nam2012//pressreleases/nam08.html