Big find: Massive black hole in small galaxy
LOS ANGELES — Astronomers on the hunt for supermassive black holes have discovered one so monstrous that its mass dominates the central hub of its galaxy in a way that defies scientists’ expectations about how typical black holes behave.
Described Wednesday in the journal Nature, the black hole may push theorists to revamptheir ideas of how these mysterious structures grow and evolve.
Astrophysicists said they are scratching their heads at how this black hole — in the galaxy NGC 1277, some 220 million light-years away — hogs its galactic bed.
Supermassive black holes typically account for just 0.1 percent of the mass in a galaxy’s stellar bulge, the cluster of older stars huddled around the center. This particular black hole, by contrast, takes up 59 percent of that central mass, shattering the previous known record of 11 percent.
“This is an oddball,” said University of California at Berkeley astrophysicist Chung-Pei Ma, whowas not part of the research. “It’s a very big black hole for a small galaxy — that’s the most surprising part.”
An international team of scientists documented the giant black hole while peering at the centers of about 800 of the biggest galaxies in the local universe. The assumption was that the biggest galaxies would hold the biggest black holes.
Their calculations revealed that the black hole at the center of NGC1277 held the mass of 17 billion suns. (The Milky Way’s black hole is a mere 4 million solar masses.) And yet this black hole, one of the largest known, dominates a galaxy that is a mere 10th the size and mass of the Milky Way.