Bastano le prime righe di questo articolo a renderlo più che interessante, oltre alla splendida foto:
http://www.nasa.gov/chandra/multimedia/galactic-pyrotechnics.html#.U7XBI_l_uMM
A galaxy about 23 million light years away is the site of impressive, ongoing fireworks. Rather than paper, powder and fire, this galactic light show involves a giant black hole, shock waves and vast reservoirs of gas.
Interessante anche questo passaggio:
The supermassive black hole at the center of NGC 4258 is about ten times larger than the one in the Milky Way and is consuming material at a faster rate, potentially increasing its impact on the evolution of its host galaxy.