Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ESA’s XMM-Newton gains deep insights into the distant Universe

15.07.2003


Using XMM-Newton, astronomers have obtained the world’s deepest ‘wide screen’ X-ray image of the cosmos to date. Their observations show newly discovered clusters of galaxies and provide insights into the structure of the distant Universe…



Unlike grains of sand on a beach, matter is not uniformly spread throughout the Universe. Instead, it is concentrated into galaxies like our own which themselves congregate into clusters. These clusters are ‘strung’ throughout the Universe in a web-like structure. Astronomers have studied this large-scale structure of the nearby Universe but have lacked the instruments to extend the search to the large volumes of the distant Universe.

Thanks to its unrivalled sensitivity, in less than three hours, ESA’s X-ray observatory XMM-Newton can see back about 7000 million years to a cosmological era when the Universe was about half its present size, and clusters of galaxies more tightly packed. Marguerite Pierre, CEA Saclay, France, with a European and Chilean team, used this ability to search for remote clusters of galaxies and map out their distribution.


The work heralds a new era of studying the distant Universe. The optical identification of clusters shows only the galaxies themselves. However, X-rays show the gas in between the galaxies – which is where most of the matter in a cluster resides. This is like going from seeing a city at night, where you only see the lighted windows, to seeing it during the daytime, when you finally get to see the buildings themselves.

Tracking down the clusters is a painstaking, multi-step process. In tandem with XMM-Newton, the team uses the four-metre Canada-France-Hawaii Telescope (CFHT), on Mauna Kea, Hawaii, to take an optical snapshot of the same region of space. A tailor-made computer program combs the XMM-Newton data looking for concentrations of X-rays that suggest large, extended structures. These are the clusters and represent only about 10% of the detected X-ray sources (the others are mostly distant active galaxies).

When the program finds a cluster, it zooms in on that region and converts the XMM-Newton data into a contour map of X-ray intensity, which it then superimposes on the CFHT optical image. The astronomers use this to check if anything is visible within the X-ray emission. If it is, the work then shifts to one of the world’s largest telescopes, the European Southern Observatory (ESO) Very Large Telescope where the astronomers identify the individual galaxies in the cluster and take ‘red-shift’ measurements. These give a measurement of the cluster’s distance.

In this way, Pierre and colleagues are mapping the distribution of galaxy clusters of the distant Universe, for the first time in astronomy. "Galaxy clusters are the largest concentrations of matter in the Universe and XMM-Newton is extremely efficient at finding them," says Pierre.

Although the task is still a work in progress, first results seem to confirm that the number of clusters 7000 million years ago is little different from that of today. This behaviour is predicted by models of the Universe that expand forever and drive the galaxy clusters further and further apart.

Eventually, it will be possible for the team to use their results to determine whether the expansion of the Universe is accelerating, as indicated by some other recent observations, or decelerating, as traditionally thought.

Monica Talevi | alfa
Further information:
http://www.esa.int/export/esaCP/SEM6SHXO4HD_Expanding_0.html

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 >>>