"We are excited about this findingbecause we can finally look back at the time when quasars formed in softgamma rays," she said. "You have to understand that until 10 years agoor so, we only had two or three [such objects] detected in soft gamma rays,and these too were at the limits of detection, so pretty uncertain."

Telescopes like the Compton Gamma RayObservatory, launched in 1991 and the source of the data the team usedto hone in on quasar 4C71.07, have given astronomers the ability to seeobjects that emit bursts and jets of gamma rays at the outer edges of ouruniverse, which extends 12 to 15 billion light-years away.

The Burst and Transient Source Experiment,or BATSE, instrument on the Earth-orbiting telescopescans the sky all the time, collecting and measuring gamma rays from varioussources. The team combined images from successive passes by the swatchof sky in Ursa Major where the quasar is located. Their data show thatthe quasar probably harbors a super-massive black hole -- the ultra-denserelic of a galactic core. Quasar 4C71.07 was discovered in optical lightin 1989. Quasars resemble stars but release energy with the power of morethan 1,000 galaxies.

The finding proves that astronomerscan detect quasars at a great distance in the gamma-ray range -- the mostenergetic form of electromagnetic radiation, said Angela Malizia, a graduatestudent at the University of Southampton, U.K.

In visible light, 4C 71.07 is lessthan impressive, just a distant speck of light. It's in radio and in X-rays-- and now, gamma rays -- that this object really shines. Credit: NASA/GoddardSpace Flight Center.

Gamma rays, non-visible energy burststhat blitz past Earth about once a day from random points in the sky, werediscovered by accident in the 1960s.

They are invisible to humans, are about1 million times more powerful than optical light, yet invisible. Astronomersthink they are created during the universe's most cataclysmic events.

Eventually, the team plans to use thedata to learn more about the structure of the universe and how galaxiesform, as well as about the class of quasars to which this object belongs-- "blazars," or objects that emit significant radiation at all wavelengths.

The black hole at the center of thequasar probably is surrounded by a ring or cloud of gas and stars thatgradually fall into the matter-sucking vacuum, said William Paciesas, ofthe University of Alabama. He is part of a team at NASA's Marshall SpaceFlight Center in Alabama that developed ways to analyze archived Comptondata.

When that matter goes down the drain,it is heated to high energies and emits lots of X-rays and gamma rays,Paciesas said.

"It seems that for many [such objects],the peak power is emitted in the soft gamma-ray range accessible to BATSE,"he said. With such measurements, astronomers could observe large numbersof high-energy sources over long periods of time, he said.

The finding also could help scientistslearn about the cosmic diffuse gamma-ray background -- high-energy radiationthat blankets the universe.

Bassani said she wants to learn howblazars behave -- both when they are closer to Earth, or far away -- soastronomers can calculate the total amount of energy they contribute tothe universe, as well as figure out how much of the cosmic gamma-ray blanketis made up of blazars and quasars, in general.