The jagged "X"

Hubble images show mysterious area long presumed to be huge black hole

The Hubble Space Telescope has photographed an enormous jagged "X" that marks the spot where scientists suspect a massive black hole lurks at the heart of a spiral galaxy 20 million light-years away.

Holland Ford of Johns Hopkins University and the Space Telescope Science Institute in Baltimore discussed the images at an astronomy meeting Monday. He said the X "is silhouetted across the glowing nucleus of the galaxy M51, known as the Whirlpool, and appears to be a vast field of gas and dust that is being sucked in by the presumed black hole.

The thickest, longest bar of the "X" is most likely a rotating doughnut, or torus, of relatively cold gas and dust about 100 light-years, or 600 trillion miles, in diameter, he said. The doughnut is seen edge on and appears as a two-dimensional bar.

If scientists are right, "M51 provides the first direct view of a torus which both fuels a massive black hole and hides the hole," Ford said. The second, smaller bar of the X, so far, is a mystery, he said, but it is probably more dust.

His team announced the finding at a meeting of the American Astronomical Society in Columbus, Ohio.

A black hole is a theoretical object so compact that nothing, not even light, can escape its immense gravitational force. The one suspected in the Whirlpool, for example, is estimated to have the mass of more than 1 million stars the size of the sun, compressed to a relatively tiny point. If light cannot escape, the hole itself is invisible, so astronomers hunt these monsters by looking for the gravity-driven violence theorists say they generate.

There is growing evidence that massive attraction of black holes may energize many galaxies of varying age and type. Supermassive versions may power quasars, the most brilliant objects in the universe, which are believed to represent an early period of galactic evolution.

The new images from the Hubble's Planetary Camera are the latest in a series from the orbital observatory that, despite its well-known flaws, have revealed unprecedented details of processes near suspected black holes.

Ford said he was "completely surprised" by the new detail that the Hubble's equipment saw at the core. "But now that we see it, it makes perfect sense."