Supermassive Black Holes Shape Their Host Galaxies With Powerful Winds

Eddie Gonzales Jr. – MessageToEagle.com – Supermassive black holes shape their host galaxies with powerful winds that sweep away interstellar matter, a new study based on data from ESA’s XMM-Newton X-ray observatory, shows.

Researchers observed the black hole at the core of an active galaxy known as PG 1114+445, showing how ultrafast winds—outflows of gas emitted from the accretion disk very close to the black hole—interact with the interstellar matter in central parts of the galaxy.

Artist’s impression showing how ultrafast winds blowing from a supermassive black hole interact with interstellar matter in the host galaxy, clearing its central regions from gas. ESA/ATG medialab

These outflows have been spotted before but the new study clearly identifies, for the first time, three phases of their interaction with the host galaxy.

“These winds might explain some surprising correlations that scientists have known about for years but couldn’t explain,” lead author Roberto Serafinelli of the National Institute of Astrophysics in Milan, Italy, said in a press release.

“For example, we see a correlation between the masses of supermassive black holes and the velocity dispersion of stars in the inner parts of their host galaxies. But there is no way this could be due to the gravitational effect of the black hole. Our study for the first time shows how these black hole winds impact the galaxy on a larger scale, possibly providing the missing link.”

Astronomers have previously detected two types of outflows in the X-ray spectra emitted by the active galactic nuclei, the dense central regions of galaxies known to contain supermassive black holes. The so-called ultra-fast outflows (UFOs), made of highly ionised gas, travel at speeds up to 40 percent the speed of light and are observable in the vicinity of the central black hole.

In the new study, the scientists describe a third type of outflow that combines characteristics of the previous two: the speed of a UFO and the physical properties of a warm absorber.

“We believe that this is the point when the UFO touches the interstellar matter and sweeps it away like a snowplough,” said Serafinelli. “We call this an ‘entrained ultra-fast outflow’ because the UFO at this stage is penetrating the interstellar matter. It’s similar to wind pushing boats in the sea.”

This entraining happens at a distance of tens to hundreds light years away from the black hole. The UFO gradually pushes the interstellar matter away from the central parts of the galaxy, clearing it from gas and slowing down the accretion of matter around the supermassive black hole.

Read more – here.

Paper

Written by Eddie Gonzales Jr. – MessageToEagle.com Staff