Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dim future for universe as stellar lights go out

07.08.2003


The universe is gently fading into darkness according to three astronomers who have looked at 40,000 galaxies in the neighbourhood of the Milky Way. Research student Ben Panter and Professor Alan Heavens from Edinburgh University´s Institute for Astronomy, and Professor Raul Jimenez of University of Pennsylvania, USA, decoded the "fossil record" concealed in the starlight from the galaxies to build up a detailed account of how many young, recently-formed stars there were at different periods in the 14-billion-year existence of the universe. Their history shows that, for billions of years, there have not been enough new stars turning on to replace all the old stars that die and switch off. The results will be published in the Monthly Notices of the Royal Astronomical Society on 21 August 2003.



"Our analysis confirms that the age of star formation is drawing to a close", says Alan Heavens. "The number of new stars being formed in the huge sample of galaxies we studied has been in decline for around 6 billion years - roughly since the time our own Sun came into being."

Astronomers already had evidence that this was the case, mainly from observing galaxies so far away that we see them as they were billions of years ago because of the great length of time their light has taken to reach us. Now the same story emerges strongly from the work of Panter, Heavens and Jimenez, who for the first time approached the problem differently and used the whole spectrum of light from an enormous number of nearby galaxies to get a more complete picture.


Galaxies shine with the combined light of all the stars in them. Most of the light from young stars is blue, coming from very hot massive stars. These blue stars live fast and die young, ending their lives in supernova explosions. When they have gone, they no longer outshine the smaller red stars that are more long-lived. Many galaxies look reddish overall rather than blue - a broad sign that most star formation happened long ago.

In their analysis, Panter, Heavens and Jimenez have used far more than the simple overall colours of the galaxies, though. The spectrum observations they used come from the Sloan Digital Sky Survey and the volume of data involved was so vast, that the researchers had to develop a special lossless data compression method, called MOPED, to allow them to analyse the sample in a reasonable length of time, without losing accuracy.

Contact:

Prof Raul Jimenez
Assistant Professor of Physics & Astronomy
Dept of Physics & Astronomy, University of Pennsylvania
Phone: +1-215 - 573-5630
Fax : +1-215 - 898-2010
e-mail: raulj@physics.upenn.edu

Prof. Alan Heavens | alfa
Further information:
http://www.sdss.org

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 proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>