Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Giant Magnetic Fields in the Universe

22.03.2017

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the diameter of the Milky Way, they host a large number of such stellar systems, along with hot gas, magnetic fields, charged particles, embedded in large haloes of dark matter, the composition of which is unknown.


Radio map of the relic at the outskirts of the galaxy cluster CIZA J2242+53 in a distance of about two billion light years, observed with the Effelberg radio telescope at 3 cm wavelength

Maja Kierdorf et al., 2017, A&A 600, A18


The 100-m radio telescope near Bad Münstereifel-Effelsberg. The observations of polarized radio emission from galaxy clusters were performed with this telescope at wavelengths of 3 and 6 cm.

Norbert Junkes/MPIfR

Collision of galaxy clusters leads to a shock compression of the hot cluster gas and of the magnetic fields. The resulting arc-like features are called “relics” and stand out by their radio and X-ray emission. Since their discovery in 1970 with a radio telescope near Cambridge/UK, relics were found in about 70 galaxy clusters so far, but many more are likely to exist. They are messengers of huge gas flows that continuously shape the structure of the universe.

Radio waves are excellent tracers of relics. The compression of magnetic fields orders the field lines, which also affects the emitted radio waves. More precisely, the emission becomes linearly polarized. This effect was detected in four galaxy clusters by a team of researchers at the Max Planck Institute for Radio Astronomy in Bonn (MPIfR), the Argelander Institute for Radio Astronomy at the University of Bonn (AIfA), the Thuringia State Observatory at Tautenburg (TLS), and colleagues in Cambridge/USA.

They used the MPIfR’s 100-m radio telescope near Bad Münstereifel-Effelsberg in the Eifel hills at wavelengths of 3 cm and 6 cm. Such short wavelengths are advantageous because the polarized emission is not diminished when passing through the galaxy cluster and our Milky Way. Fig.1 shows the most spectacular case.

Linearly polarized relics were found in the four galaxy clusters observed, in one case for the first time. The magnetic fields are of similar strength as in our Milky Way, while the measured degrees of polarization of up to 50% are exceptionally high, indicating that the emission originates in an extremely ordered magnetic field. “We discovered the so far largest ordered magnetic fields in the universe, extending over 5-6 million light years”, says Maja Kierdorf from MPIfR Bonn, the project leader and first author of the publication.

She also wrote her Master Thesis at Bonn University on this subject. For this project, co-author Matthias Hoeft from TLS Tautenburg developed a method that permits to determine the “Mach number”, i.e. the ratio of the relative velocity between the colliding gas clouds and the local sound speed, using the observed degree of polarization. The resulting Mach numbers of about two tell us that the galaxy clusters collide with velocities of about 2000 km/s, which is faster than previously derived from measurements of the X-ray emission.

The new Effelsberg telescope observations show that the polarization plane of the radio emission from the relics turns with wavelength. This “Faraday rotation effect”, named after the English physicist Michael Faraday, indicates that ordered magnetic fields also exist between the clusters and, together with hot gas, cause the rotation of the polarization plane. Such magnetic fields may be even larger than the clusters themselves.

„The Effelsberg radio telescope proved again to be an ideal instrument to detect magnetic fields in the universe“, emphasizes co-author Rainer Beck from MPIfR who works on this topic for more than 40 years. “Now we can systematically search for ordered magnetic fields in galaxy clusters using polarized radio waves.”


The research team comprises of Maja Kierdorf, Rainer Beck, Matthias Hoeft, Uli Klein, Reinout van Weeren, William Forman, and Christine Jones. First author Maja Kierdorf and Rainer Beck are MPIfR employees.

Original publication:

Relics in galaxy clusters at high radio frequencies, M. Kierdorf, R. Beck, M. Hoeft, U. Klein, R. J. van Weeren, W. R. Forman, and C. Jones, 2017, Astronomy & Astrophysics 600, A18 (March 22, 2017): https://doi.org/10.1051/0004-6361/201629570

Contact:

Maja Kierdorf,
Max-Planck-Institut für Radioastronomie, Bonn.
Phone: +49 228 525-180
E-mail: kierdorf@mpifr-bonn.mpg.de

Dr. Rainer Beck,
Max-Planck-Institut für Radioastronomie, Bonn
Phone: +49 6221 528-323
E-mail: rbeck@mpifr-bonn.mpg.de

Dr. Norbert Junkes,
Press and Public Outreach
Max-Planck-Institut für Radioastronomie, Bonn.
Phone: +49 228 525-399
E-mail: njunkes@mpifr-bonn.mpg.de

Weitere Informationen:

http://www.mpifr-bonn.mpg.de/pressreleases/2017/4

Norbert Junkes | Max-Planck-Institut für Radioastronomie

More articles from Physics and Astronomy:

nachricht UNH scientists help provide first-ever views of elusive energy explosion
16.11.2018 | University of New Hampshire

nachricht NASA keeps watch over space explosions
16.11.2018 | NASA/Goddard Space Flight Center

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: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>