A Galactic 'Supervolcano' - No Kidding

"Galactic 'Supervolcano' Seen Erupting With X-Rays"
Space.com (September 6, 2010)

"A galactic 'supervolcano' in the massive galaxy M87 is erupting, blasting gas outwards. The cosmic volcano — driven by a giant black hole in M87's center — is preventing hundreds of millions of new stars from forming.

"An image, taken by NASA's Chandra X-ray Observatory and the National Radio Astronomy Observatory's Very Large Array, captures the drama in action.

" 'Our results show in great detail that supermassive black holes have a surprisingly good control over the evolution of the galaxies in which they live,' said Norbert Werner of the SLAC National Accelerator Laboratory in Melo Park, Calif., who led one of two studies of M87's black hole and its effects. 'The black hole's reach extends ever farther into the entire cluster, similar to how one small volcano can affect practically an entire hemisphere on Earth.'..."

That "supervolcano" remark isn't empty hyperbole. Although the space in and around a galaxy is pretty close to being a vacuum, there's a sort of 'atmosphere' of particles, atoms, and molecules. And x-rays from M87's black hole affect that ultra-thin gas in ways that are similar to the ways plumes from volcanoes affect our atmosphere.

On a much larger, and slower, scale of course.