Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rapid galaxy merging dominates universe’s early history

20.02.2006


A new study by a researcher at The University of Nottingham has provided the first observational evidence of how massive galaxies in our universe formed.



The results of this study have major implications for many other areas of research and are being used by astronomers to explain seemingly unrelated processes such as how massive black holes and the universe’s stars came to be.

The research, led by Dr. Christopher J. Conselice of the University’s School of Physics and Astronomy, is published in the February 20th edition of the Astrophysical Journal.


It uses the deepest images taken by the Hubble Space Telescope to study galaxies when they were only two billion years old. His team has found that the majority of the most massive galaxies in the early universe are undergoing multiple and spectacular mergers.

These mergers lead to the creation of new stars from colliding gas clouds and likely feed and grow the masses of black holes lurking in the centre of all galaxies.

The work is helping to definitively confirm what scientists have long hoped for - massive galaxies form when smaller galaxies merge together - a major and previously unconfirmed prediction of the cosmological standard model.

"The results show us that the most massive galaxies we see in today’s universe, which are passive and old, were once undergoing rapid mergers with each other, which it turns out is how they form," said Conselice.

While distant galaxies have been studied for over a decade, it has until now remained a mystery how they evolved into the galaxies we see today. Young galaxies have very low masses and astronomers have long been puzzled by how these systems turn into massive galaxies in the local universe.

The Conselice results demonstrate that a typical massive galaxy in today’s universe has undergone four to five mergers with other galaxies to transform from these young low mass systems into the giant galaxies.

These mergers are very rare today, with only about one per cent of galaxies merging, whereas 10 billion years ago, nearly all massive galaxies were undergoing mergers. An analysis technique developed by Conselice over a period of more than 10 years was used on the deepest images ever taken of the universe to make these discoveries.

The results further show that massive galaxies did not form rapidly, within a few million years after the Big Bang, neither did they form gradually over an extended period of time. In a surprising finding, almost all of this merger activity occurred from the birth of the universe to about six billion years ago.

Dr. Conselice added: "Perhaps the most amazing thing about these results is that massive galaxy formation is largely over when the universe is half its current age. This means that all this merging activity was somehow curtailed by an unknown process."

The research may hold clues about the formation of our own galaxy. The Milky Way contains spiral arms, which are not thought to form through the merger process. However, at the centre of our galaxy is a spherical system of stars called a bulge - a high-density region featuring many old stars and a massive black hole, which probably formed as a result of these mergers.

The research could also help astronomers to see into the Milky Way’s future - it is possible that our galaxy will itself merge with Andromeda, our nearest neighbouring large galaxy in around a billion years from now. This would see the destruction of the spiral disk that surrounds the bulge and change dramatically the shape of our galaxy, as well as significantly altering the positions of stars we see in the night sky.

Dr. Christopher J. Conselice | alfa
Further information:
http://www.nottingham.ac.uk/~ppzcc1/massivegal.html

More articles from Physics and Astronomy:

nachricht MSU astronomers discovered supermassive black hole in an ultracompact dwarf galaxy
14.08.2018 | Lomonosov Moscow State University

nachricht ASU astrophysicist helps discover that ultrahot planets have starlike atmospheres
13.08.2018 | Arizona State 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: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>