Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Missing link found between old and young star clusters

08.01.2003


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 Heating quantum matter: A novel view on topology
22.08.2017 | Université libre de Bruxelles

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Stretchable biofuel cells extract energy from sweat to power wearable devices

22.08.2017 | Power and Electrical Engineering

New technique to treating mitral valve diseases: First patient data

22.08.2017 | Medical Engineering

IVAM Marketing Prize recognizes convincing technology marketing for the tenth time

22.08.2017 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>