Are Quasars the Products Of Peculiar Galaxies?

By now, much of the scientific community accepts Astronomer Maarten Schmidt's contention that the faint stars called quasars are the most distant objects ever observed (TIME cover, March 11). But challengers remain, and they have by no means given up. Schmidt's colleague, Halton Arp of the Mount Wilson and Palomar observatories, for example, believes that quasars were ejected from odd-looking galaxies that are, by cosmological standards, virtual neighbors to the earth.

Arp worked out his novel theory after compiling an atlas of the "peculiar galaxies" that appear to have been distorted by cataclysmic explosions. Many of these distorted galaxies, he noted, were located at just about the midpoint of a line joining a pair of nearby radio sources. Most of these sources are radio galaxies, but eight have been identified as quasars. Furthermore, filaments of matter from several of the peculiar central galaxies appear to extend out in the direction of the radio sources.

Unknown Cause. It is more than coincidence, says Arp in an article in Science, that so many of the quasars and radio galaxies appear to lie so close to the peculiar galaxies in the sky. The explanation, he believes, is that they were formed from great masses of matter expelled from exploding central galaxies between 10 million and one billion years ago. If they were formed in this manner, he concludes, they must still be relatively close to their parent galaxies, which are located only 30 million to 300 million light-years from the earth. They would not have reached the cosmological distances suggested by Schmidt.

Arp acknowledges that light from the quasars shows a substantially greater red shift than light from the galaxies that he thinks gave them birth. But he is not bothered by the problem; unlike most astronomers he does not believe that the red shift is caused by the speed with which quasars are receding from the earth--a speed that would indicate they are billions of light-years away. Instead, says Arp, the red shift could be caused by an immense quasar gravitational field, by the high velocity of material falling toward the center of quasars that are suffering catastrophic collapse, or by "some as yet unknown cause."

Back to the Drawing Board. Such speculations have caused a stir among astronomers, who are impressed by Arp's statistics. But many are equally impressed by his failure to account for the energy needed to expel quasars and radio galaxies from his collection of "peculiar galaxies." And most point out that he has offered only informed guesses, no scientific evidence that the red shift of quasar light is caused by anything other than their speed of recession. "If Arp is right," says one astronomer, "we have to abandon most of our work of the past 30 years, drop the general theory of relativity and go back to our drawing boards"--something few of Arp's colleagues are yet ready to do.

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