Baby booms and birth control in space

September 25, 2007
Stars

Stars in galaxies are a bit similar to people: during the first phase of their existence they grow rapidly, after which a stellar birth control occurs in most galaxies. Thanks to new observations from Dutch astronomer Mariska Kriek with the Gemini Telescope on Hawaii and the Very Large Telescope in Chile, it is now known that a part of the heavy galaxies already stopped forming stars when the universe was still a toddler, about three billion years old.

Astronomers suspect that black holes exert an influence on this halt in births.

Heavy galaxies are a boring phenomenon in the modern universe. They have an elliptical or a round form, the stars are evenly distributed over the galaxies and no more new stars are formed. The large quantities of stars, about 10 billion, and the current, low birth rate point to the fact that star formation must have been much higher in the past. When were these stars formed and why did the star formation subsequently stop?

The finite speed of light makes it possible to study the universe when it was much younger than now. With the help of spectrographs, such as the Gemini Near-InfraRed Spectrograph and SINFONI on the VLT, Mariska Kriek and her colleagues studied 36 heavy galaxies in the early universe. These galaxies are so far away that the light from them has taken 11 billion years to reach us.

Interestingly the researchers found no signs of star formation for a large proportion of the galaxies observed. This new discovery contributes to the growing mass of evidence that the formation of new stars in heavy galaxies is strongly inhibited after an explosive baby boom.

This 'halt in births' is possibly due to the influence of the enormous black holes in the middle of the galaxies. The large amount of material attracted by these black holes generates enormous quantities of energy that subsequently heats up the gas in the galaxy. As a result of this heating the gas is no longer able to form new stars. The researchers did indeed discover a black hole in a number of the galaxies they investigated. These were mainly the galaxies where the star formation was inhibited less than 1 billion years ago. These results support the idea that black holes limit the birth of new stars.

Source: Netherlands Organization for Scientific Research

3.5 /5 (2 votes)  

Rank 3.5 /5 (2 votes)
Tags

Related Stories
Relevant PhysicsForums posts
  • Never ending outer space.....
    created13 hours ago
  • Neutron Star fragments?
    created15 hours ago
  • stationary or not?
    created19 hours ago
  • Scale of the Universe
    createdFeb 10, 2012
  • Titan's lack of impact craters
    createdFeb 09, 2012
  • Real pictures of black hole eating a star?
    createdFeb 08, 2012
  • More from Physics Forums - General Astronomy

More news stories

Latin America mining boom clashes with conservation

Latin America is experiencing a mining boom as prices rise fuelled by a hike in global demand, but the region is also being hit by a wave of violent protests, strikes and rallies by environmentalists.

Space & Earth / Environment

created 6 hours ago | popularity not rated yet | comments 0

Political leaders play key role in how worried Americans are by climate change: study

More than extreme weather events and the work of scientists, it is national political leaders who influence how much Americans worry about the threat of climate change, new research finds.

Space & Earth / Environment

created Feb 06, 2012 | popularity 5 / 5 (6) | comments 72

NASA budget will axe Mars deal with Europe: scientists

US President Barack Obama's budget proposal to be submitted next week for 2013 will cut NASA's budget by 20 percent and eliminate a major partnership with Europe on Mars exploration, scientists said Thursday.

Space & Earth / Space Exploration

created Feb 10, 2012 | popularity 5 / 5 (3) | comments 55

Humans may have helped the decline of African rainforests 3000 years ago

(PhysOrg.com) -- Large areas of rainforests in Central Africa mysteriously disappeared over three thousand years ago, to be replaced by savannas. The prevailing theory has been that the cause was a change ...

Space & Earth / Environment

created Feb 10, 2012 | popularity 4.1 / 5 (14) | comments 20 | with audio podcast report

Study shows global glaciers, ice caps, shedding billions of tons of mass annually

Earth's glaciers and ice caps outside of the regions of Greenland and Antarctica are shedding roughly 150 billion tons of ice annually, according to a new study led by the University of Colorado Boulder.

Space & Earth / Earth Sciences

created Feb 08, 2012 | popularity 4.4 / 5 (9) | comments 14 | with audio podcast


Google might launch Drive for cloud storage soon

(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...

Love a click away in Indonesia's Twitter Republic

He was a geeky kid from Yogyakarta, she a glamorous city girl in Jakarta. In a country with one of the world's most vibrant social networking scenes they fell in love on Twitter.

Europeans protest controversial Internet pact

Tens of thousands of people marched in protests in more than a dozen European cities Saturday against a controversial anti-online piracy pact that critics say could curtail Internet freedom.

Walney offshore wind farm is world's biggest (for now)

(PhysOrg.com) -- The Walney wind farm on the Irish Sea--characterized by high tides, waves and windy weather--officially opened this week. The farm is treated in the press as a very big deal as the Walney ...

Navy to begin tests on electromagnetic railgun prototype launcher

The Office of Naval Research (ONR)'s Electromagnetic (EM) Railgun program will take an important step forward in the coming weeks when the first industry railgun prototype launcher is tested at a facility ...

Explained: Sigma

It's a question that arises with virtually every major new finding in science or medicine: What makes a result reliable enough to be taken seriously? The answer has to do with statistical significance -- but ...