UM astronomers find water clouds in Pisces

June 02, 1994|By Frank D. Roylance | Frank D. Roylance,Sun Staff Writer

It could be the ultimate in long-range weather observations.

University of Maryland radio astronomers say they have spotted water clouds near the center of a galaxy called Markarian 1, a smudge of stars 200 million light years away in the constellation Pisces.

It is the most distant water detected in the universe.

"It's always exciting to find a superlative," said James Braatz of Greenbelt, a UM doctoral candidate who led the research as part of his work on the structure of "active" galaxies, those believed to be powered by black holes.

The discovery of water so far from Earth was not unexpected and does not suggest the presence of life there. But its detection at such a distance helps to enlarge astronomers' understanding of "megamasers," a curious natural phenomenon that amplifies normally weak radio emissions from water at the centers of active galaxies.

Mr. Braatz was assisted by UM astronomy professor Andrew Wilson and Christian Henkel of the Max Planck Institute for Radioastronomy in Germany. They were to announce their discovery today at a meeting of the American Astronomical Society in Minneapolis.

At the same meeting, astronomers from the Johns Hopkins University said this week that they have found "very strong" evidence for a black hole with a mass of several million suns at the center of the Andromeda galaxy.

It is the second black hole discovery announced in less than a week.

Black holes are objects with gravitation so powerful that they draw in stars and anything else that passes near, including light.

The detection of molecular water clouds in Markarian 1 was made using a huge radiotelescope near Effelsberg, 40 miles south of Bonn, Germany. The largest steerable radiotelescope in the world, its dish antenna is more than 100 yards wide.

"It's not a surprise that there is water [in Markarian 1] because it has been seen in galaxies much closer to us," said Mr. Braatz. "But it is a surprise that it's bright enough to be detectable."

That brightness is believed to be the result of a natural amplifier called a "megamaser." ("Mega" means very large. "Maser" stands for "microwave amplification by the stimulated emission of radiation.")

Astronomers say water megamasers form when an energy source -- perhaps gas being sucked into a black hole -- stimulates the water molecules to emit powerful microwaves. The phenomenon is similar to man-made lasers that stimulate rubies or other substances to produce powerful beams of visible light.

Radio telescopes can detect natural masers, and hundreds of small ones have been found in the Milky Way. But megamasers are a million times stronger, much rarer, and they're found outside our galaxy. Only nine have been detected so far, four of them by Mr. Braatz, a 27-year-old Baltimore native.

Johns Hopkins scientists said that they have not proved the presence of a black hole in Andromeda, but their evidence is the strongest yet.

Hopkins astrophysicist Yichuan Pei said the Hubble Space Telescope -- before its December repairs -- clocked matter near the galaxy's center swirling at 850,000 miles an hour, suggesting a nearby object with a mass of several million suns.

Andromeda, a spiral galaxy similar to our own Milky Way, lies 2.4 million light years away in the northern sky.

NASA announced last week the first conclusive evidence for the presence of a massive black hole at the core of M87, an elliptical galaxy 50 million light years away in the constellation Virgo.

The black hole discoveries, both made with the Hubble Space Telescope, suggest that black holes might be a common feature of galactic cores.

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