Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Giant galaxy’s violent past comes into focus

11.05.2004


Long-exposure images of the giant elliptical galaxy M87 by NASA’s Chandra X-ray Observatory, together with radio observations, have provided spectacular evidence of repetitive outbursts from the vicinity of the galaxy’s supermassive black hole. Magnetized rings, bubbles, plumes and jets ranging in size from a few thousand to a few hundred thousand light years point to ongoing violent activity for hundreds of millions of years.


Chandra image of the giant elliptical galaxy M87 (NASA/CXC)



"The hot X-ray emitting gas extending for hundreds of thousands of light years around M87 reveals a record of episodes of black hole activity," said Paul Nulsen of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. and an author of an Astrophysical Journal paper describing the latest Chandra observations. "With these detailed observations, we are beginning to understand how the central supermassive black hole transfers enormous amounts of energy over vast reaches of space."

M87, located in the middle of the Virgo galaxy cluster, is surrounded by an extensive atmosphere of multi-million degree Celsius gas. Chandra’s long-exposure image has allowed astronomers to see in more detail structures discovered by previous observations with Chandra and other X-ray telescopes, to discover new features, and to make specific comparisons with radio images, which trace the presence of high-energy electrons in a magnetic field.


The picture that emerges is one in which the infall of material toward a central supermassive black hole produces a magnetized jet of high-energy particles that blasts away from the vicinity of the black hole at near the speed of light. As a jet plows into the surrounding gas, a buoyant, magnetized bubble of high-energy particles is created, and an intense sound wave rushes ahead of the expanding bubble.

In Chandra’s image of M87, X-rays from the jet dominate the central region of the galaxy. The jet is thought to be pointed at a small angle toward the line of sight, out of the plane of the image. Bright arcs around dark cavities of faint X-ray emission appear to be gas that has been swept up on rising, buoyant bubbles that were created a few million years ago (in M87 time — M87 is 50 million light years from Earth). These bubbles, which rise like hot air from a fire or explosion in the atmosphere, show up as bright regions in radio images. An alternative interpretation, presented in the June 1, 2004 issue of Astrophysical Journal Letters by Hua Feng of Tsinghau University in China and colleagues, is that the rings are shock waves that surround the jet and are seen in projection.

An image processed to bring out faint features reveals two circular rings with radii of 45 thousand and 55 thousand light years, respectively. These features are likely sound waves produced by earlier explosions about 10 million and 14 million years ago, respectively. A very faint arc at an even larger distance has a probable age of 100 million years.

Spectacular, curved X-ray plumes extending from the upper left to the lower right illustrate in dramatic fashion how the central black hole can affect the galaxy and its environment over huge distances. The arm on the upper left extends more than 75 thousand light years, and the one on the lower right more than 100 thousand light years from the center of the galaxy. These features are thought to be gas carried out from the center of the galaxy on buoyant bubbles created by outbursts tens of millions of years ago.

A growing body of evidence from other galaxy clusters suggests that episodic outbursts from supermassive black holes in giant, centrally located galaxies are a common feature. These outbursts, which produce magnetized jets and bubbles of high energy particles, along with mammoth sound waves, could be due to the self-regulated inflow of gas into the black hole — gas around the black hole cools and flows inward to feed the black hole, producing an outburst which shuts down the inflow for a few million years, at which point the cycle begins again. Or, the cause could be a much more dramatic event, like the cannibalization of a smaller galaxy, with the subsequent merger of two supermassive black holes in the center.

The results from Nulsen’s team, which included William Forman and other colleagues from the CfA, were based on approximately 40 hours of Chandra observations with its Advanced CCD Imaging Spectrometer. Andrew Young of the University of Maryland in College Park, and colleagues, have published a paper identifying many of the X-ray features in M87 in the November 10, 2003 issue of The Astrophysical Journal based on a shorter Chandra observation.

NASA’s Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA’s Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Steve Roy | MSFC
Further information:
http://www1.msfc.nasa.gov/NEWSROOM/news/releases/2004/04-135.html

More articles from Physics and Astronomy:

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

nachricht New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>