Black Hole: Too Big For Its Galaxy

It turns out that the truly massive black hole that exists in a recently discovered galaxy is far larger than current theories of space evolution would have it. Astronomers at the U.K.'s Keele University and University of Central Lancashire recently published their findings on the black hole in the journal Monthly Notices of the Royal Astronomical Society.

The black hole is in the galaxy SAGE0536AGN and was first discovered using NASA's Spitzer Space Telescope and viewing in infrared light. That galaxy is believed to be 9 billion years old or more, and it has an active galactic nucleus (AGN). That's a very bright object that is created by the accretion of gas by a huge black hole. As the gas accelerates in the result of velocities from the black hole's massive gravitational field, the gas emits light, according to a release.

By measuring the speed of the gas moving around the black hole, the scientists determined the size of the hole itself. They used the Southern African Large Telescope to look at a hydrogen emission line. It was in the galaxy spectrum, where light forms its individual colors, much like in a prism. The researchers could also see that the spectrum was made wider by the Doppler Effect. By looking at the amount of broadening, they could infer that the gas was moving at high speed, as the release noted.

The research found SAGE0536AGN's black hole to be 350 million times the Sun's mass. Because the galaxy itself has already been figured at 25 billion solar masses, the galaxy is 70 times the size of the black hole. The astronomers say that in this case, the black hole is 30 bigger than it ought to be for the size of its galaxy, according to a release.

"Galaxies have a vast mass, and so do the black holes in their cores. This one though is really too big for its boots -- it simply shouldn't be possible for it to be so large," said Dr Jacco van Loon, an astrophysicist at Keele University and the lead author on the new paper, in the release.

The researchers say that in normal cases, a black hole would grow at the same rate as its galaxy, the release said.