Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Super-star clusters may be born small and grow by coalescing

12.01.2005


A trio of massive, young star clusters found embedded in a star cloud may shed light on the formation of super-star clusters and globular clusters.


Lower right: a blue image of the spiral galaxy M101 from the Second Palomar Observatory Sky Survey. The box marks the location of NGC 5461.Lower left: A false color image of NGC 5461 made from images taken with the Hubble Space Telescope Wide-Field Planetary Camera 2 using filters F547M, F675W, and F656N (displayed in blue, green, and red, respectively). Young stars and clusters will appear predominantly blue, while the ionized interstellar gas appears red. Credits: NASA, Y.-H. Chu and R. Chen (University of Illinois), and K. Johnson (University of Virginia).
Upper left: A close-up of the core of NGC 5461 taken with the Hubble Space Telescope Advanced Camera for Surveys using the F435W filter to show the clusters and surrounding star cloud.
Credits: NASA, K.D. Kuntz (University of Maryland Baltimore County).



The discovery, made with images taken with the Hubble Space Telescope, is being presented today by You-Hua Chu and Rosie Chen of the University of Illinois at Urbana-Champaign and Kelsey Johnson of the University of Virginia to the American Astronomical Society meeting in San Diego. This finding indicates that super-star clusters may be formed by coalescence of smaller clusters.

The tightly packed group of clusters was found in the core of the active star formation region NGC 5461, within an arm of the giant spiral galaxy M101. This galaxy is located about 23 million light-years away in the constellation Ursa Major (the Big Dipper).


"NGC 5461 has such a high concentration of light in its core that some astronomers have thought it might host a super-star cluster," said Chu, who is a professor of astronomy at Illinois and principal investigator of the project. Super-star clusters, with a total mass of up to 1 million times that of the sun, are five to 50 times more massive than the spectacular R136 cluster at the center of the Tarantula Nebula in the Large Magellanic Cloud. They are believed to be the young counterparts of the massive globular clusters in our galaxy. Hubble Space Telescope images of the core of NGC 5461 revealed a tight group of three massive clusters surrounded by a cloud of stars within a region about 100 light-years in diameter. Although each cluster is comparable to the R136 cluster, the total mass within this small volume is similar to that of a super-star cluster.

"If NGC 5461 were several times farther away, even the Hubble Space Telescope would be unable to resolve this tight group of clusters," said Chen, a graduate student at Illinois. "It is possible that some of the super-star clusters previously reported in distant galaxies actually consist of groups of clusters similar to NGC 5461."

The large amount of mass at the core of NGC 5461 produces a strong gravitational field, causing the clusters and stars to move and interact dynamically. The rapidly fluctuating gravitational field produced by this interaction dissipates the relative motion of the clusters into random motions of individual stars. Eventually, the clusters and surrounding star cloud will merge into one single star cluster. "The Hubble Space Telescope images of NGC 5461 provide a unique glimpse of a super-star cluster in the making," said Johnson, a professor of astronomy at Virginia. "There is no super-star cluster yet, but it is just a matter of time."

The dynamical evolution of the clusters at the core of NGC 5461 is being simulated by astronomy professor Paul Ricker at Illinois. Preliminary results show that under optimal conditions these clusters may merge within a few million years. "Fortunately, NGC 5461 is near enough, and young enough for us to resolve it with the Hubble Space Telescope," Chu said. "We were indeed lucky to catch it at such an opportune time."

James E. Kloeppel | EurekAlert!
Further information:
http://www.uiuc.edu

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

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: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Targeting headaches and tumors with nano-submarines

20.07.2018 | Health and Medicine

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>