Hubble Finds a Smoldering Remnant in a Blast From the Past
In some science fiction movies there is a sleeping monster, like Godzilla, who suddenly awakens and goes on a rampage. Our Milky Way galaxy was once thought to have a sleeping monster at its core, a black hole weighing 4 million times our Sun's mass. But there is increasing evidence the black hole occasionally awakens to devour a hapless star or gas cloud that falls into it. The black hole then burps out powerful "death-ray" beams of radiation and particles traveling at nearly the speed of light. The biggest outburst on record was 2 million years ago. This is evident in expanding plumes of plasma that form an hourglass shape, extending far above and below the plane of our galaxy. Bipolar shock waves from the black hole outburst heated the gas outside the galactic plane to glow in gamma-rays and X-rays.
Hubble has found circumstantial evidence that the black hole is still smoldering long after the earlier outburst. Hubble astronomers' evidence is like doing an archeological dig to try and peer through the interstellar pollution of dense sheets of dust and gas between Earth and the galactic center, 27,000 light-years away. Hubble photographed a bright knot of gas that has been impacted by an invisible jet from the black hole, that is merely 15 light-years from it. The black hole must have shown brilliantly billions of years ago as a quasar (quasi-stellar object), when our young galaxy was feeding on lots of infalling gas. But after all this time the black hole still goes through fits and starts, and is not ready for napping as long as there is a snack around.
Find additional articles, images, and videos at HubbleSite.org
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