- News Home
5 December 2013 11:26 am ,
Vol. 342 ,
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
Hubble Sees Quasars in Diverse Abodes
19 November 1996 7:00 pm
WASHINGTON, D.C.--The latest pictures from the Hubble Space Telescope, unveiled here today at NASA headquarters, reveal that the enigmatic cosmic lighthouses known as quasars reside in many more kinds of galaxies than scientists had previously thought.
Astronomers John Bahcall of the Institute for Advanced Study in Princeton, New Jersey, and Michael Disney of the University of Wales in Cardiff have imaged 34 nearby quasars and their stellar neighborhoods, providing the clearest view yet of the mysterious objects that produce more light than trillions of suns combined. The images confirm that quasars exist not as lonely beacons but as components of a wide variety of galaxies: regular spirals, regular ellipticals, and many irregular galaxies undergoing collisions or other distortions.
A primary reason for building the space telescope, says Disney, was to get a better look at quasars, which have long puzzled scientists with their concentrated, bright light. Ground-based observations had hinted that they exist as part of galaxies, but the quasars are so bright that they obscure their relatively dim surroundings. And Earth's atmosphere distorts the view even more. The new images, taken from the unencumbered vantage point of space, are a "big step forward," Bahcall says. "We now have clear pictures of the homes and environments of quasars."
More controversial, however, is whether the images shed light on how quasars form. According to Bahcall, "We do not have a simple picture--we have a mess." Disney disagrees. He claims to see evidence for galactic collisions surrounding 11 of the 15 quasars his group imaged. Because such collisions are relatively rare, Disney says, this suggests they have something to do with quasar formation.