Far-Out Quasars

Their red shifts seem to be a reliable yardstick

Horrid quasar Near or far.

This truth to you 1 must confess:

My heart for you is full of hate O super star.

Imploded gas, Exploded trash, You glowing speck upon a plate, Of Einstein's world you 've made a mess!

First identified in the 1960s, the enigmatic, starlike objects called quasars are as baffling today as they were more than a decade ago when Astronomer Jesse Greenstein scribbled his poetic plaint on a Caltech blackboard. What sets quasars apart from most other celestial objects is that the light they emit is shifted drastically toward the red, or low-frequency, end of the spectrum. Just as a train whistle's lowered pitch indicates that it is moving away from the listener, so the quasars' light suggests that they are receding from the earth at tremendous speeds--some approaching the universe's ultimate speed limit, the velocity of light. And according to a law formulated by Astronomer Edwin Hubbell in 1929, the greater the red shift of light from a galaxy, or island of stars, the farther away the galaxy is from the earth. Indeed, using the red shift from some quasars as a yardstick indicates that they could be 10 billion or more light-years away--making them the farthermost objects ever observed in the heavens by astronomers.

But that poses a dilemma for physicists. If quasars are really so far away, yet bright enough to be detected through ordinary optical and radio telescopes, they must be radiating more energy than 50 to 100 galaxies, each of which contains hundreds of billions of stars. Yet careful measurements by radio telescopes indicate that a quasar is much smaller than a galaxy and perhaps no bigger than a solar system. The problem: no physical process yet known to scientists can generate such incredible energy in so tiny a volume.

This quandary has led some astronomers to suggest that the quasars' red shifts are caused by something other than their great distance. Perhaps the light is simply "tired" after its long journey and is arriving at a lower frequency. Or it might be "stretched" toward the red by the strong gravitational field of the quasar. Another possibility: maybe quasars have been exploded out of nearby galaxies at great velocities. Any of these explanations could leave the quasars near enough to the earth to account for their observed brightness, and at the same time give them their enormous red shifts. But are any of these theories right?

Now Astronomer Joseph S. Miller, using the Lick Observatory's powerful 120-in. (3-meter) telescope near San Jose, Calif., has produced powerful new evidence to support the "distant" quasar argument. Expanding on earlier work at the Hale Observatories by Beverley Oke and James Gunn with the 200-in. (5-meter) Palomar telescope, he and two colleagues studied one of the so-called BL Lacertae objects, which until the late 1960s were thought to be ordinary variable stars, but now are known to resemble quasars.

The object picked by Miller was a quasar-like structure surrounded by an old, spherical galaxy. When the Miller group measured the red shift of light from that galaxy, the astronomers determined that the island of stars was 1 billion light-years away. And because the quasar-like object was imbedded in the galaxy, it was presumably the same great distance from the earth. Furthermore, the galaxy's brightness was consistent with that distance. Miller's conclusion: if the red shift was indeed a correct yardstick for an object that so closely resembled a quasar, it probably was accurate as well for quasars themselves, including those that seem to be at the very "edge" of the observable universe.

Still, Miller concedes, he is no closer than before to learning what quasars are or what gives them their awesome power. Some astronomers now believe that quasars may be a stage in the evolution of galaxies. Others speculate that they may be galaxies with "black holes" --the remnants of giant, collapsed stars --at their centers. Matter from the surrounding galaxy drawn by tremendous gravitational forces into these holes could be compressed and heated enough to produce huge amounts of energy. Perhaps the most bizarre idea is that quasars are "white holes," portals through space and time linking our universe and a mirror-image universe composed of antimatter. When antimatter from that other world comes in contact with the "normal" matter of our own, the two totally annihilate each other. That kind of reaction, involving a complete conversion of mass into energy, could explain the prodigious energy output of the quasars.

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