Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

H.E.S.S. discovers radio galaxy shining in gamma light

30.03.2009
An international team of astrophysicists, for the first time, has observed very-high-energy gamma radiation from a nearby active galactic nucleus, the radio galaxy Centaurus A.

The weak radiation has been discovered by the H.E.S.S. telescopes in Namibia, currently one of the most sensitive instruments of high-energy astrophysics. (The Astrophysical Journal Letters 695, L40-L44, 2009)

Active galactic nuclei are the most energetic objects in the Universe. Around the suspected supermassive black hole they harbour at their centre, charged particles (electrons and protons) may be accelerated to velocities close to the speed of light and ejected in oppositely directed jets. Centaurus A, located in the constellation Centaurus, is one of the brightest galaxies in the night sky and the nearest radiogalaxy with an active nucleus. Its proximity enables unique studies of the active centre and its surrounding. Centaurus A covers an area of the sky more than 100 times the size of the area of the full moon - but this extended structure only glows in radio frequencies with only the host galaxy being visible to the naked eye.

The telescopes of the High Energy Stereoscopic System (H.E.S.S.) in Namibia have now, for the first time, observed very-high-energy gamma-ray emission from Centaurus A. H.E.S.S. consists of four identical telescopes with 13 m mirror diameter and is operated by an international collaboration, coordinated by the Max-Planck-Institut für Kernphysik in Heidelberg. Ultrafast cameras record the weak blue flashes that arise when very-high-energy gamma-ray photons are absorbed in the atmosphere and create cascades of subatomic particles, so-called particle showers.

The high-energy gamma radiation from Centaurus A is so weak that more than 100 hours of observation time were needed to obtain a picture. The detected emission originates from the centre of the galaxy and the inner parts of the jets. With the current data, however, it is not yet possible to identify the exact origin of the emission. These gamma rays - a trillion times more energetic than visible light - are produced, it is thought, when particles, accelerated to extreme energies in the vicinity of a black hole, interact with radiation fields or the surrounding medium.

The detection of very-high-energy gamma rays from Centaurus A poses the more general question of whether such emission might be a common feature of active galactic nuclei. To answer this question, further observations of Centaurus A and of other active galactic nuclei are necessary. In that case, future instruments with higher sensitivity will be able to detect many more sources than previously anticipated and so better determine the processes involved.

A very large telescope with a mirror diameter of 30 m to extend the H.E.S.S. experiment is already under construction and will start observation in 2010. For the future, the European project Cherenkov Telescope Array (CTA) is planned. This gamma-ray observatory will consist of roughly 100 telescopes, leading to an improvement in sensitivity by a factor 10 compared to the current generation of instruments.

Contact:

Dr. Martin Raue
Max-Planck-Institut für Kernphysik, Heidelberg
Tel.: +49-6221-516-470
E-Mail: martin.raue@mpi-hd.pg.de
Prof. Dr. Werner Hofmann
Max-Planck-Institut für Kernphysik, Heidelberg
Tel.: +49-6221-516-330
E-Mail: Werner.Hofmann@mpi-hd.mpg.de
Prof. Dr. Felix Aharonian
Institute for Advanced Studies, Dublin, Ireland
Max-Planck-Institut für Kernphysik, Heidelberg
Tel.: +49-6221-516-485
E-Mail: Felix.Aharonian@mpi-hd.mpg.de
Jean-Phillipe Lenain
LUTH - OBSPM, Paris, France
Tel.: +33 1 45 07 74 19
E-Mail: jean-philippe.lenain@obspm.fr
Weitere Informationen:
http://www.iop.org/EJ/abstract/1538-4357/695/1/L40 original article
http://arxiv.org/abs/0903.1582 preprint server
http://www.mpi-hd.mpg.de/hfm/HESS/ H.E.S.S. Experiment Homepage
http://www.obspm.fr/actual/nouvelle/mar09/cena.en.shtml l'Observatoire de Paris
http://www.eso.org/gallery/v/ESOPIA/Galaxies/phot-03a-09-fullres.tif.html Detailed explanations, enlarged resolution

http://www.mpifr-bonn.mpg.de/public/pr/pic-cena-dt.html MPIfR, Bonn, press information about the image

Dr. Bernold Feuerstein | Max-Planck-Institut
Further information:
http://www.mpi-hd.mpg.de

More articles from Physics and Astronomy:

nachricht Turning entanglement upside down
22.05.2018 | Universität Innsbruck

nachricht Astronomers release most complete ultraviolet-light survey of nearby galaxies
18.05.2018 | 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: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>