Featured Research

from universities, journals, and other organizations

Most distant galaxy cluster revealed by invisible light

Date:
May 13, 2010
Source:
Max Planck Institute for Extraterrestrial Physics
Summary:
An international team of astronomers from Germany and Japan has discovered the most distant cluster of galaxies known so far -- 9.6 billion light years away. The X-ray and infrared observations showed that the cluster hosts predominantly old, massive galaxies, demonstrating that the galaxies formed when the universe was still very young. These and similar observations therefore provide new information not only about early galaxy evolution but also about history of the universe as a whole.

This false colour image is 3.4 arcmin on a side (about 1/10 the size of the moon). The arrows indicate galaxies that are likely located at the same distance, clustered around the centre of the image. The contours indicate the X-ray emission of the cluster. Galaxies with confirmed distance measurements of 9.6 billion light years are circled. The combination of the X-ray detection and the collection of massive galaxies unequivocally proves a real, gravitationally bound cluster.
Credit: Institute for the Physics and Mathematics of the Universe, Japan

An international team of astronomers from Germany and Japan has discovered the most distant cluster of galaxies known so far -- 9.6 billion light years away. The X-ray and infrared observations showed that the cluster hosts predominantly old, massive galaxies, demonstrating that the galaxies formed when the universe was still very young. These and similar observations therefore provide new information not only about early galaxy evolution but also about history of the universe as a whole.

Clusters of galaxies are the largest building blocks in the universe. Our galaxy, the Milky Way, is part of the Virgo cluster, comprising some 1000-2000 galaxies. By observing galaxies and clusters that are very distant from Earth, astronomers can look back in time, as their light was sent out a long time ago and took millions or billions of years to reach the astronomers' telescopes.

An international team of astronomers from the Max Planck Institute for Extraterrestrial Physics, the University of Tokyo and the Kyoto University has now discovered the most distant cluster of galaxies observed so far. X-ray observations in the Subaru XMM Deep Field helped to identify the candidates, and infrared observations using the Subaru telescope provided the distance information. A particularity of this discovery consists in using infrared wavelengths, invisible to the naked eye. This is dictated by the expansion of the universe, which forces distant galaxies to have large velocities, shifting their light away from visible to infrared wavelengths. The Multi-Object Infrared Camera and Spectrometer (MOIRCS) at the Subaru telescope works at near-infrared wavelengths, where the galaxies are most luminous.

"The MOIRCS instrument has an extremely powerful capability of measuring distances to galaxies. This is what made our challenging observation possible," says Masayuki Tanaka from the University of Tokyo. "Although we confirmed only several massive galaxies at that distance, there is convincing evidence that the cluster is a real, gravitationally bound cluster."

That the individual galaxies are indeed held together by gravity is confirmed by observations in a very different wavelength regime: The matter between the galaxies in clusters is heated to extreme temperatures and emits light at much shorter wavelengths than visible to the human eye. The team therefore used the XMM-Newton space observatory to look for this radiation in X-rays.

"Despite the difficulties in collecting X-ray photons with a small effective telescope size similar to the size of a backyard telescope, we detected a clear signature of hot gas in the cluster," explains Alexis Finoguenov from the Max Planck Institute for Extraterrestrial Physics.

The combination of these different observations in (to the eye) invisible wavelengths therefore led to the pioneering discovery of the galaxy cluster at a distance of 9.6 billion light years -- some 400 million light years further into the past than the previously most distant cluster known.

An analysis of the data collected about the individual galaxies shows that the cluster contains already an abundance of evolved, massive galaxies that formed some two billion years earlier. As the dynamical processes for galaxy aging are slow, presence of these galaxies requires the cluster assembly through merger of massive galaxy groups, each nourishing its dominant galaxy. The cluster is therefore an ideal laboratory for studying the evolution of galaxies, when the universe was only about a third of its present age.

As distant galaxy clusters are also important tracers of the large scale structure and primordial density fluctuations in the universe, similar observations in the future will lead to important information for cosmologists. The results obtained so far demonstrate that current near infrared facilities are capable of providing a detailed analysis of distant galaxy populations and that the combination with X-ray data is a powerful new tool. The team therefore is continuing the search for more distant clusters.


Story Source:

The above story is based on materials provided by Max Planck Institute for Extraterrestrial Physics. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. Tanaka, A. Finoguenov, Y. Ueda. A spectroscopically confirmed X-ray cluster at z=1.62 with a possible companion in the Subaru/XMM-Newton deep field. Astrophysical Journal Letters, 2010; (accepted for publication) [link]

Cite This Page:

Max Planck Institute for Extraterrestrial Physics. "Most distant galaxy cluster revealed by invisible light." ScienceDaily. ScienceDaily, 13 May 2010. <www.sciencedaily.com/releases/2010/05/100512164920.htm>.
Max Planck Institute for Extraterrestrial Physics. (2010, May 13). Most distant galaxy cluster revealed by invisible light. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2010/05/100512164920.htm
Max Planck Institute for Extraterrestrial Physics. "Most distant galaxy cluster revealed by invisible light." ScienceDaily. www.sciencedaily.com/releases/2010/05/100512164920.htm (accessed July 22, 2014).

Share This




More Space & Time News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com
Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, July 18, 2014

This Week @ NASA, July 18, 2014

NASA (July 18, 2014) Apollo 11 yesterday, Next Giant Leap tomorrow, Science instruments for Europa mission, and more... Video provided by NASA
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins