The Quasi-Quasars

As astronomers probe outward in space, they are looking backward in time, because the light that they see from very distant objects started its journey millions of years ago. They see the light from stars that no longer exist, and chart strange, starlike objects that could hold the secret of how the universe began. Quasars (for quasi-stellar radio sources) are the most intriguing of these objects, the oldest and most brilliant things in the observable universe, and the sources of powerful and mysterious radio waves. Now astronomers have identified a new class of quasi-stellar objects shining out of the past.

These are quasi-stellar blue galaxies --sort of quasi-quasars. Caltech's Dr. Allan Sandage described them in the Astrophysical Journal last week, adding that he suspected them of being "very distant, superbright galaxies reaching more than halfway to the horizon of the universe." Like quasars, they resemble stars, are up to 100 times as bright as an ordinary galaxy, and are receding from earth at tremendous speeds. Unlike quasars, they emit no radio energy.

Spectral Patterns. For years, astronomers observed objects known as "blue stars"--stars that are so hot that a large part of the light they give is blue. While studying quasars with the Palomar telescope, Sandage got interested in the blue stars, and he found that a number of them seemed to be "interlopers" among the quasars. Those closest to earth, he discovered, are the familiar blue stars. But some of those fainter than 14.5 magnitude are remarkably similar to quasars. When photographed with blue filters, they show an excess of ultraviolet energy, which is a characteristic of quasars.

The speed at which the blue objects travel is the most convincing proof of their great distance from earth: under the expanding-universe theory, the faster an object recedes from the earth, the farther away it is. Using spectroscopic techniques perfected by Dr. Maarten Schmidt, a Caltech colleague, Sandage and Schmidt analyzed three of these objects, and found that they were moving away from the earth at tremendous speeds. One of them, BSO-1 (blue stellar object) seems to be speeding at the rate of 125,000 miles a second, making it second only to quasar 3C-9 (149,000 miles a second) as the most distant known object. The spectral patterns also showed a presence of ionized carbon atoms that have been detected previously only in the most distant quasars. The blue objects probably outnumber quasars 500 to 1 and are scattered throughout the universe--the nearest one being" 20 million light-years from earth.

Measuring Rods. Like quasars, Sandage's objects create more questions than answers. Do they represent the next evolutionary step after quasars? Will they give clues to some violent cosmic explosions of eons ago? Sandage suspects that they are galaxies in their early phases of life. "We have no idea yet what the two kinds of quasi-stellars may lead to," he concedes. "We do know that they provide us with the long-sought keys to determine the size and shape of the universe." Since the quasars and the blue galaxies are so far from the earth, the study of them should enable astronomers working with the 200-in. telescope to look back on 93% of the time since the birth of the universe.

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