Chandra finds black holes stirring up galaxies

Jan 10, 2006

Black holes are creating havoc in unsuspected places, according to a new study of images of elliptical galaxies made by NASA's Chandra X-ray Observatory. The discovery of far-reaching explosive activity, due to giant central black holes in these old galaxies, was a surprise to astronomers.

The Chandra data revealed an unsuspected turmoil in elliptical galaxies that belies their calm appearance in optical light. Astronomers believe massive clouds of hot gas in these galaxies have been stirred up by intermittent explosive activity from centrally located super-massive black holes.

"This is another example of how valuable it is to observe the universe at different wavelengths besides just the traditional optical wavelengths," said NASA's Chandra Program Scientist Wilt Sanders. "Without these X-ray and radio observations, we wouldn't know these apparently static galaxies in reality are still evolving due to the interaction with their central black holes."

These results came from an analysis of 56 elliptical galaxies in the Chandra data archive by associate professor Thomas Statler and doctoral candidate Steven Diehl, both of the Physics and Astronomy department at the Ohio University, Athens, Ohio. Contrary to expectations, they found the distribution of the multimillion-degree gas in these galaxies differed markedly from that of the stars.

"Most elliptical galaxies have traditionally been considered to be quiet places, like placid lakes," Statler said. "Our results show these galaxies are a lot stormier than we thought."

Previous X-ray studies have shown elliptical galaxies contain multimillion degree gas whose mass is a few percent of the stars in it. Except for rare cases, violent activity in elliptical galaxies was thought to have stopped long ago. It was expected the hot gas would have settled into an equilibrium shape similar to, but rounder, than the stars. High angular resolution imaging observations by Chandra indicate otherwise.

"We found the distribution of hot gas has no correlation with the optical shape," Diehl said. "Something is definitely making a mess there, and pumping energy equivalent to a supernova every century into the gas."

Although supernovae are a possible energy source, a more probable cause was identified. The scientists detected a correlation between the shape of the hot gas clouds and the power produced at radio wavelengths by high-energy electrons. This power output can be traced back to the centers of the galaxies, where super-massive black holes are located.

Repetitive explosive activity fueled by the in-fall of gas into central black holes is known to occur in giant elliptical galaxies located in galaxy clusters. Statler and Diehl's analysis indicates the same phenomena are also occurring in isolated elliptical galaxies.

"These results are part of an emerging picture that shows the impact of super-massive black holes on their environment is far more pervasive than previously thought," Statler said.

Source: Chandra X-ray Center

Explore further: Planck: Gravitational waves remain elusive

add to favorites email to friend print save as pdf

Related Stories

New image brings galaxy diversity to life

Jan 06, 2015

A compelling new image from Gemini Observatory peers into the heart of a group of galaxies (VV166) traveling through space together. The variety of galactic forms range from a perfect spiral, to featureless ...

The year ahead in science

Jan 05, 2015

Some serious groundwork has been laid. Some amazing instruments are turning on. Some incredible destinations are in sight. If you ask us, 2015 is going to be an awesome year in science.

Warm gas pours 'cold water' on galaxy's star-making

Dec 08, 2014

Some like it hot, but for creating new stars, a cool cosmic environment is ideal. As a new study suggests, a surge of warm gas into a nearby galaxy—left over from the devouring of a separate galaxy—has ...

Strange galaxy perplexes astronomers

Dec 02, 2014

With the help of citizen scientists, a team of astronomers has found an important new example of a very rare type of galaxy that may yield valuable insight on how galaxies developed in the early Universe. ...

Studying the physics of galaxies

Nov 03, 2014

Assistant Professor of Astronomy Evan Kirby arrived on campus in August. Born and raised in New Orleans, Kirby earned his BS in 2004 from Stanford University; his undergraduate thesis involved trips to Pasadena ...

Recommended for you

Planck: Gravitational waves remain elusive

11 hours ago

Despite earlier reports of a possible detection, a joint analysis of data from ESA's Planck satellite and the ground-based BICEP2 and Keck Array experiments has found no conclusive evidence of primordial ...

Going a long way to do a quick data collection

17 hours ago

Like many a scientist before me, I have spent this week trying to grow a crystal. I wasn't fussy, it didn't have to be a single crystal – a smush of something would have done – just as long as it had ...

How are planets formed?

18 hours ago

How did the Solar System's planets come to be? The leading theory is something known as the "protoplanet hypothesis", which essentially says that very small objects stuck to each other and grew bigger and ...

What's happening in the universe right now?

18 hours ago

There are some topics that get a little frustrating in their pedantry, but can really draw attention to the grand scope and mechanics in our Universe. This is definitely one of them.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.