Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Missing link found between old and young star clusters


One and a half billion years ago the small, inconspicuous galaxy Messier 82 (M82) almost smashed into its large, massive neighbour galaxy Messier 81 (M81), causing a frenzy of star formation.

New research by astronomers from the Universities of Cambridge and Utrecht, Netherlands, has now discovered an elusive phenomenon in this violent "starburst" area. About 100 star clusters have been discovered that are believed to be the ancestors of the so-called "globular clusters" thought to be the oldest building blocks of galaxies.

"Such an intermediate-age population of massive, compact star clusters has been searched for extensively, but unsuccessfully until now," said Dr Richard de Grijs from the University of Cambridge’s Institute of Astronomy, and lead scientist on the project. "The fact that we have finally found such a population is evidence that formation of long-lived star clusters is indeed happening now, just as it has in the early Universe and ever since."

Dr de Grijs and his colleagues Henny Lamers and Nate Bastian, using images of M82 from the Hubble Space Telescope, found a population of about 100 star clusters aged 1.5 billion years. This is half-way down its evolution to old age - it is thought the star clusters could survive the next 10 billion years.

M82, which is 11 million light years away, is the closest starburst galaxy to Earth and is close enough to allow Hubble to see many individual star clusters.

During M82’s collision with its neighbouring galaxy, M81, the interstellar gas clouds were strongly compressed because of gravitational effects of the mass of M81, causing intense star formation activity.

Such strong starbursts have not occurred in our Milky Way galaxy for billions of years and none, until this discovery, have yet evolved sufficiently far.

"Clusters are disrupted much faster in M82 than here," said Dr de Grijs. "This is probably another after-effect of the near collision with M81. M82 has a more disturbed appearance than other nearby, well-behaved galaxies because of the more inhomogeneous distribution of interstellar gas in the galaxy caused by the near collision."

Stars are most often born in large clusters, originating from gas clouds that collapse due to their self-gravitation.

Astronomers have found thousands of star clusters in and around our Milky Way galaxy, and the populations of star clusters in neighbouring galaxies have been charted extensively as well.

Since all stars in a cluster - ranging from 1000 up to a million or more - are born more or less simultaneously, a cluster’s age can be determined fairly accurately; star clusters can therefore be used as astronomical "clocks", tracing the events that created them.

The most ancient clusters in our Milky Way galaxy - so-called "globular clusters" - are about 12 billion years old, older than the Milky Way in its present form. These globular clusters have always been considered the oldest building blocks of galaxies.

The majority of galaxies go through epochs in which the rate of star formation rises explosively, a so-called starburst. Such epochs can be traced back through the ages of star clusters: entire populations of star clusters of roughly similar age are found to form during such starburst events.

However, a strange anomaly persisted in the observations: both young, unevolved and old, fully evolved star cluster populations were known - and such populations continue to be detected routinely - but clusters half-way on that career track were missing.

This anomaly gave credibility to the theory that cluster formation in the early Universe was fundamentally different from that at present.

However, since cluster formation is closely associated with the formation and evolution of stars and galaxies in general, fundamental doubts about the evolution of the Universe as a whole were raised.

The research team consists of: Dr Richard de Grijs, Institute of Astronomy, University of Cambridge Professor Henny Lamers and Mr. Nate Bastian, Astronomical Institute, Utrecht University, The Netherlands. This research will be published in The Astrophysical Journal (Letters) of 20 January 2003.

Laura Morgan | alfa

More articles from Physics and Astronomy:

nachricht Sharpening the X-ray view of the nanocosm
23.03.2018 | Changchun Institute of Optics, Fine Mechanics and Physics

nachricht Drug or duplicate?
23.03.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

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: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>