Highlights of Current VLA Observations 
1-31 January 2008 

Studying a Giant Hole in the Universe

Last summer, astronomers announced that, using data from the VLA, they had discovered a huge void, or "hole," in the Universe, nearly a billion light-years across and containing almost no matter. This month, they are making detailed observations of this region to confirm the finding and refine their determination of the void's distance from Earth. Continued study of this huge void will help scientists understand the evolution of large-scale structure in the Universe and the nature of the mysterious "dark energy" that appears to be accelerating the expansion of the Universe.

Star Formation and Gas in Nearby Galaxies

Scientists who earlier used the Hubble Space Telescope (HST) to study a number of nearby galaxies in great detail now are using the VLA to study the distribution of hydrogen gas in those same galaxies. The VLA images of the gas in the galaxies will show about the same level of detail seen in the HST visible-light images. The combination of visible-light and radio images will allow the astronomers to better understand how star formation is triggered in the galaxies and how the outflows from young stars interact with the thin gas that pervades the galaxies.

Gamma Ray Bursts

The VLA will be used by astronomers looking for radio emission from the "fireballs" presumed to result from the explosions that cause cosmic bursts of Gamma rays. This month, they are monitoring the fireball of a burst detected on January 25, and still visible to the VLA. In May 1997, the VLA made the first-ever detection of radio waves coming from a Gamma Ray Burster, and measured the emission from that object for months afterward. As satellites with gamma-ray detectors continue to give rapid notice of these bursts, the VLA, along with other ground-based observatories, will seek to detect the objects at wavelengths longer than those of gamma rays. The VLA also has detected radio emission from many other Gamma Ray Bursters since then.

Modified on Tuesday, 20-Jan-2009 10:13:47 MST