Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dazzling Halos illuminate our dusty Galaxy

26.01.2004


The discovery of a unique phenomenon: a beautiful set of expanding X-ray halos surrounding a gamma-ray burst which have never been seen before, (see Movie link at end), has been announced by an international team of astronomers led by Dr Simon Vaughan of the University of Leicester. The research has been accepted for publication in the Astrophysical Journal.



Gamma-ray bursts (GRB) are the most energetic form of radiation in the Universe and can be used to probe any material between Earth and the burst. In this case, the GRB lies behind the plane of our Galaxy, so its light has to travel through the gas and dust in the Galactic disc to reach us.

ESA’s gamma ray observatory satellite ’Integral’ detected the 30 second long GRB 031203 on December 3rd 2003 and the halos were discovered in a follow-up observation that started 6 hours after the burst with ESA’s ’XMM-Newton’ X-ray space telescope.


Commenting on the discovery, Professor Ian Halliday, Chief Executive of the UK’s Particle Physics and Astronomy Research Council (PPARC) said “Gamma-ray bursts are the most violent events in the Universe. Unlike the serene beauty of the stars that we can see with our eyes, the Gamma Ray Universe is a place of dramatic explosions, cosmic collisions and matter being sucked into black holes.”

Halliday added “This is a wonderful example of two of ESA’s most advanced observatories in which UK scientists have made a significant contribution, working in harmony to reveal a new level of scientific understanding.”

The fading X-ray emission from the GRB - the afterglow - is clearly seen in the image from the X-ray cameras on XMM-Newton. Uniquely, two rings centred on the afterglow were also seen. Dr Vaughan said "These rings are due to dust in our own Galaxy which is illuminated by the X-rays from the gamma-ray burst. The dust scatters some of the X-rays causing the rings, in the same way as fog scatters the light from a car’s headlights." He added "It’s like a shout in a cathedral; the shout of the gamma-ray burst is louder, but the Galactic reverberation, seen as the rings, is more beautiful."

Due to the finite speed of light, X-rays from more distant dust reach us later, giving rise to the appearance of expanding rings. Dr Vaughan said "We expect to see an expanding ring on the sky if the dust is in a sheet roughly in the plane of the sky, but as we see two rings there must be two dust sheets between us and the GRB. Understanding how dust is distributed in our Galaxy is important. Dust helps cool gas clouds which can then collapse to form stars and planets. Knowing where dust is located helps astronomers determine where star and planet formation is likely to occur."

Expanding X-ray dust scattering rings have never been seen before. Slower moving rings seen in visible light around a very few supernovae are caused by a similar effect.

The two halos are due to thin sheets of dust at 2,900 and 4,500 light-years away; the astronomers accurately measured the distances from the expansion rate of the halos. The distances have an uncertainty of just 2%, a remarkable level of accuracy for an object in our Galaxy. The nearest dust sheet is probably part of the Gum nebula, a bubble of hot gas resulting from many supernova explosions. The GRB itself is thought to have occurred in a small galaxy about a billion light-years away (one of the closest GRB galaxies).

Astronomers are still trying to understand the mysterious gamma-ray bursts. Some occur with the supernova explosion of a massive star when it has used up all of its fuel, although only stars which have lost their outer layers and which collapse to make a black hole seem able to make a GRB.

Today Integral and XMM-Newton provide astronomers with their most powerful facilities for studying gamma-ray bursts, but 2004 will see the launch of "Swift", a new NASA mission with major UK involvement, which will be dedicated to GRBs. This will work in concert with the two ESA satellite observatories, providing more opportunities for discoveries in this cutting edge field. UK participation in Integral, XMM-Newton and Swift is funded by the Particle Physics and Astronomy Research Council.

Julia Maddock | PPARC
Further information:
http://www.pparc.ac.uk

More articles from Physics and Astronomy:

nachricht Seeing the quantum future... literally
16.01.2017 | University of Sydney

nachricht Airborne thermometer to measure Arctic temperatures
11.01.2017 | Moscow Institute of Physics and Technology

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: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>