Seeking the source of gamma-ray bursts.For a fleeting moment, gamma-ray bursts radiate ra·di·ate v. 1. To spread out in all directions from a center. 2. To emit or be emitted as radiation. ra more energy than any quasar quasar (kwā`sär), one of a class of blue celestial objects having the appearance of stars when viewed through a telescope and currently believed to be the most distant and most luminous objects in the universe; the name is shortened from , then they vanish without a trace. Their brief and unpredictable appearances make it difficult to determine whether these flashes originate within the Milky Way or far beyond. Gamma-ray bursts have not been definitively linked to any known star, galaxy, or other celestial object. If these bursts do come from distant sources, they probably lie in galaxies. Although astronomers have yet to find a smoking gun-a particular galaxy from which a burst has emerged-Samuel B. Larson, Ian S. McLean, and Eric E. Becklin of the University of California, Los Angeles UCLA comprises the College of Letters and Science (the primary undergraduate college), seven professional schools, and five professional Health Science schools. Since 2001, UCLA has enrolled over 33,000 total students, and that number is steadily rising. have done the next-best thing. Using infrared telescopes, which can detect galaxies hidden by dust, they surveyed small patches of sky around the locations of several bright gamma-rays bursts. The observations reveal that, on average, these regions contain twice as many galaxies as similar regions in which no gamma-ray bursts have been found. In addition, the estimated distance of these galaxies from Earth, their luminosity luminosity, in astronomy, the rate at which energy of all types is radiated by an object in all directions. A star's luminosity depends on its size and its temperature, varying as the square of the radius and the fourth power of the absolute surface temperature. , and their distribution within the patch suggest that one of them could be the source of a burst. "These observations offer the first direct connection between gamma-ray bursts and another class of objects," the team reports. Theorist Leonid Ozernoy of George Mason University Named after American revolutionary, patriot and founding father George Mason, the university was founded as a branch of the University of Virginia in 1957 and became an independent institution in 1972. in Fairfax, Va., says the study provides supporting evidence that bursts originate outside our galaxy. |
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