Now, measure universe 3 times farther using super-sharp radio ‘eye’By ANI
Monday, February 21, 2011
WASHINGTON - Scientists have managed to increase their ability to measure the cosmos three times farther thanks to the super-sharp radio ‘vision’ of astronomy’s most precise telescope.
This may have important implications for numerous areas of astrophysics, including determining the nature of Dark Energy, which constitutes 70 percent of the Universe.
The continent-wide Very Long Baseline Array (VLBA) also is redrawing the map of our home Galaxy and is poised to yield tantalizing new information about extrasolar planets, among many other cutting-edge research projects.
The VLBA provides the greatest ability to see fine detail, called resolving power, of any telescope in the world. It can produce images hundreds of times more detailed than those from the Hubble Space Telescope.
This power allows astronomers to make precise cosmic measurements with far-ranging implications for research within our own Galaxy and far beyond.
New measurements with the VLBA have placed a galaxy called NGC 6264 at a distance of 450 million light-years from Earth, with an uncertainty of no more than nine percent. This is the farthest distance ever directly measured, surpassing a measurement of 160 million light-years to another galaxy in 2009.
Previously, distances beyond our own Galaxy have been estimated through indirect methods.
“Our direct, geometric measurements are independent of the assumptions and complications inherent in other techniques,” said James Braatz, of the National Radio Astronomy Observatory (NRAO).
Fine-tuning the measurement of ever-greater distances is vital to determining the expansion rate of the Universe, which helps theorists narrow down possible explanations for the nature of Dark Energy.
“Solving the Dark Energy problem requires advancing the precision of cosmic distance measurements, and we are working to refine our observations and extend our methods to more galaxies,” said Braatz.
Another ongoing project uses the VLBA to redraw the map of our own home Galaxy. Recent work has added dozens of new measurements to star-forming regions in the Milky Way, The direct VLBA measurements improve on earlier estimates by as much as a factor of two.
This improvement significantly aids in understanding the physics of the young stars and their environments. It also has changed the map of the Milky Way, indicating that our Galaxy has four spiral arms, not two, as previously thought. (ANI)