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LOS ANGELES, July 22 (Xinhua) -- Two teams of astronomers have discovered the largest and farthest reservoir of water ever detected in the universe, NASA's Jet Propulsion Laboratory (JPL) said on Friday.The water, equivalent to 140 trillion times all the water in the world's ocean, surrounds a huge, feeding black hole, called a quasar, more than 12 billion light-years away, according to JPL in Pasadena, California."The environment around this quasar is very unique in that it's producing this huge mass of water," said Matt Bradford, a scientist at JPL. "It's another demonstration that water is pervasive throughout the universe, even at the very earliest times. "This artist's concept illustrates a quasar, or feeding black hole, similar to APM 08279+5255, where astronomers discovered huge amounts of water vapor. Gas and dust likely form a torus around the central black hole, with clouds of charged gas above and below. X-rays emerge from the very central region, while thermal infrared radiation is emitted by dust throughout most of the torus. While this figure shows the quasar's torus approximately edge-on, the torus around APM 08279+5255 is likely positioned face-on from our point of view.A quasar is powered by an enormous black hole that steadily consumes a surrounding disk of gas and dust. As it eats, the quasar spews out huge amounts of energy. Both groups of astronomers studied a particular quasar called APM 08279+5255, which harbors a black hole 20 billion times more massive than the sun and produces as much energy as a thousand trillion suns.Astronomers expected water vapor to be present even in the early, distant universe, but had not detected it this far away before. There's water vapor in the Milky Way, although the total amount is 4,000 times less than in the quasar, because most of the Milky Way's water is frozen in ice. Water vapor is an important trace gas that reveals the nature of the quasar. In this particular quasar, the water vapor is distributed around the black hole in a gaseous region spanning hundreds of light-years in size (a light-year is about six trillion miles).Its presence indicates that the quasar is bathing the gas in X- rays and infrared radiation, and that the gas is unusually warm and dense by astronomical standards, JPL said.Although the gas is at a chilly minus 63 degrees Fahrenheit ( minus 53 degrees Celsius) and is 300 trillion times less dense than Earth's atmosphere, it's still five times hotter and 10 to 100 times denser than what's typical in galaxies like the Milky Way, said JPL.Measurements of the water vapor and of other molecules, such as carbon monoxide, suggest there is enough gas to feed the black hole until it grows to about six times its size, JPL said.Whether this will happen is not clear, the astronomers say, since some of the gas may end up condensing into stars or might be ejected from the quasar.Bradford's team made their observations starting in 2008, using an instrument called "Z-Spec" at the California Institute of Technology's (Caltech's) Submillimeter Observatory, a 33-foot (10- meter) telescope near the summit of Mauna Kea in Hawaii. Follow-up observations were made with the Combined Array for Research in Millimeter-Wave Astronomy (CARMA), an array of radio dishes in the Inyo Mountains of Southern California.The second group, led by Dariusz Lis, senior research associate in physics at Caltech and deputy director of the Caltech Submillimeter Observatory, used the Plateau de Bure Interferometer in the French Alps to find water. In 2010, Lis's team serendipitously detected water in APM 8279+5255, observing one spectral signature.Bradford's team was able to get more information about the water, including its enormous mass, because they detected several spectral signatures of the water, according to JPL.

BEIJING, June 29 (Xinhuanet) -- Twitter Inc. co-founders Biz Stone and Evan Williams said they are moving on from the microblogging service, media reports said Wednesday.“The Twitter crew and its leadership team have grown incredibly productive,” Stone said on the blog. “I’ve decided that the most effective use of my time is to get out of the way until I’m called upon to be of some specific use.”The two will continue to advise Twitter on strategic matters, but devote the lions' share of their time to The Obvious Corporation, Stone said.Obvious was first created by Williams to buy back a company from investors that he and Stone failed to sell about six years ago, Stone said. The two began working together after leaving Google in 2005.The company will also be run by Jason Goldman, a former Twitter executive, Stone said.

PARIS, Sept. 21 (Xinhua) -- European heavy-lift launcher Ariane 5 lifted off two communication satellites Wednesday from the Kourou launch centre in French Guiana, live broadcast of the launching process showed.The rocket, carrying the two communication satellites Arabsat 5C and SES-2, was launched at GMT 2138.This was the fifth heavy-lift mission of Ariane 5 in 2011. Arianespace had planned six Ariane 5 missions through 2011.The satellite Arabsat-5C was developed for the Arab Satellite Communications Organization (Arabsat) to provide satellite capacity in both C-band and Ka-band frequencies for a wide range of communications services.Jointly produced by Europe's EADS Astrium and Thales Alenia Space, it will be positioned at 20 degree East orbital location to cover the Middle East and Africa.Manufactured by Orbital Sciences Corporation of the United States, SES-2 will join the fleet of European satellite telecommunications operator SES, and is to be positioned at 87 degree West for coverage over North America and the Caribbean.Both Arabsat-5C and SES-2 have life-spans as long as 15 years.This Ariane 5 dual-passenger mission was postponed from Tuesday due to local strikes of French Guiana workers.Founded in 1980 as the world's first launch service and solutions company, Arianespace planned to achieve six Ariane 5 missions through 2011. Through 2010, heavy-lift workhorse Ariane 5 finished six missions, sending a dozen spacecraft into expected orbits.The next mission from Arianespace centre in Kourou was scheduled for Oct. 20 by medium-lift vehicle Soyuz. It will be Soyuz' first mission from French Guiana with a pair of satellites for Europe's Galileo satellite navigation system.

COPENHAGEN, May 30 (Xinhua) -- The number of confirmed E. coli cases has risen to 14 in Denmark, with at least 26 others suspected of having the intestinal infection, the National Serum Institute said Monday.Seven of the confirmed cases show symptoms of kidney failure which marks an advanced stage of the sickness, the institute said."Almost all of the 14 infected people have been in northern Germany recently except just one. There is a 24-year-old man from Jutland. He has not even been to Germany, so he does not quite fit with the rest of the pattern," said Kaare Moelbak, chief physician at the institute. "We do not know yet how he has been so unlucky to get this infection but we assume that it has been a person-to-person transmission, or that he has eaten infected vegetables," he added.Denmark's Veterinary and Food Administration (DVFA) had advised Danish consumers not to eat raw tomato, lettuce and cucumber from Germany, and cucumber from Spain.It is now checking Danish cucumbers for traces of E. coli, with results expected on Tuesday.

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