Donald Moffitt - Genesis 02

turned his head to look out the observation wall and saw a cross section of fire flash by, flaring from yellow to red in seconds. Yggdrasil gave a lurch.
    “What was that?” Bram said.
    “Jet,” Jun Davd said. “I’d estimate it at about twenty-five light-years long and still growing. It’s moving at about three-fourths of the speed of light, but of course it’s emitting a lot of relativistic electrons that are traveling faster.”
    Smeth looked around, strain showing on his face. “We swallowed some of the fringes. That was the bump you felt.”
    “What caused it?” Bram asked.
    Jun Davd’s composure was undisturbed despite the backhand swipe the cosmos had just taken at him. “It’s that black hole we’re heading toward. If you’ll keep your eye on it, you can see the process as it gets ready to toss the next one at us. The hole must be spinning very fast. It must have a very strange geometry—sliced off flat at the poles, but with the curvature of its circumference undisturbed. The gas and dismantled stars flowing into it would have a very strong magnetic field. You can’t anchor a magnetic field in a black hole, but some of the field lines would penetrate the accretion disk and attach themselves very close to the event horizon. Then it’s crack the whip— a million stars at a time.”
    “Why are we heading directly toward it?” Bram asked Jao. “I thought we were on a course that gave it a wide berth.”
    “We were,” Jao said, his face grim.
    “We still are,” Jun Davd’s voice said. “That object you see is not the black hole at the center of the galaxy.”
    “What is it, then?” Bram said, but he was afraid he already knew.
    “It’s another black hole—in orbit around the galaxy’s central hypermass. The black hole at the center of the galaxy has a second black hole as its satellite.”
     
    Except for those who were not able to leave their monitor boards, everyone on the bridge had gathered around the viewscreen showing Jun Davd’s display. Nobody was doing much talking.
    Bram stared, fascinated, at the flat, double-ended funnel of fire that was sucking in the stars. You couldn’t see the black hole itself, of course. You couldn’t even see the accretion disk. But you could see those whirlpools of superheated gas by the inferno of radiation they gave off as they fell down that cosmic drain. And that intense, tiny blaze at the center was where the condensed matter crossed the static limit and doomed itself to leave the universe forever.
    Jun Davd’s model of binary black holes explained a lot of things. It explained the rolling yawn of the satellite hole: that was caused by the precession of its spin axis. And it explained those fingers of fire across the bed of coals: the satellite hole was sweeping out the rotating gas cloud of its primary. The geometry of space-time must be very complicated in there. Eventually the orbit of the satellite hole would decay, and it would fall into its primary.
    And that would make quite a splash! If anyone in the nearby universe was trying to prove the existence of gravity waves, it would make his day.
    “How did it happen?” Bram said.
    “The black hole may have been snatched from the Bonfire when the two galaxies met,” Jun Davd said. “That might help to explain why the Bonfire lost its shape.”
    Jao spoke wonderingly. “That would have been quite a meal for our galaxy to digest. First it nibbles around the edges. Then it reaches in and pulls out a plum.”
    Jun Davd cackled appreciatively. “The stolen hole would have fallen to the center, sweeping up stars and gas,” he went on. “By the time it took up residence as part of a binary pair, it would have been quite massive. We can assume, from the present remnants of the Bonfire, that its central black hole could not have been much more than a hundred million solar masses. However, the satellite hole appears to be three or four times that mass. In fact, I’d put it at a fourth to a third the size of its primary, which I now estimate at well over a billion solar masses— much bigger than I expected. Or …”
    “Or?” Bram prompted.
    “Alternatively, the orbiting black hole might have been born right here in the galactic nucleus—maybe with the help of turbulence caused by the passing of the Bonfire.”
    “You don’t sound very convinced.”
    “The dust is certainly thick enough and stellar collisions frequent enough to aggregate a second black hole of a few thousand