Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

X-ray satellites catch magnetar in gigantic stellar ‘hiccup’

10.04.2007
Astronomers using data from several X-ray satellites have caught a magnetar – the remnant of a massive star with an incredibly strong magnetic field – in a sort of giant cosmic blench.

When it comes to eerie astrophysical effects, the neutron stars commonly known as magnetars are hard to beat. The massive remnants of exploded stars, magnetars are the size of mountains but weigh as much as the sun, and have magnetic fields hundreds of trillions of times more powerful than the Earth’s, which pushes our compass needles north.


Located in a star cluster about 15 000 light-years away in the Ara constellation in the southern hemisphere, the magnetar goes by the unwieldy official name CXOU J164710.2-455216. These images were taken by the European Photon Imaging Camera (EPIC), on board ESA’s XMM-Newton satellite, using 0.3-12.0 keV photons. The left panel shows the image of the field before the burst. The magnetar is brighter in the right panel, taken after the burst. A seismic event was observed on this object on September 2005 while it was being heavily observed with several satellites, including ESA’s X-ray satellite, XMM-Newton, and NASA's Swift X-ray and gamma-ray observatory. The event caused the surface of the dense star to crack and shine brightly from multiple sources. Credits: ESA/XMM-Newton/ California Institute of Technology, M.Muno

Now astrophysicists have managed to catch a recently discovered magnetar in a sort of giant cosmic hiccup that still has them puzzled. In multiple reports in the Astrophysical Journal and Monthly Notices of the Royal Astronomical Society, the researchers describe the behaviour of this body, located in a star cluster about 15 000 light-years away in the Ara constellation in the southern hemisphere. The magnetar goes by the unwieldy official name CXOU J164710.2-455216, or more informally, the ‘Westerlund 1 magnetar.’

"We only know of about a dozen magnetars," says Michael Muno, a scientist at the California Institute of Technology's Space Radiation Laboratory, and the original discoverer of the magnetar in 2005. "In brief, what we observed was a seismic event on the magnetar, which tells us a lot about the stresses these objects endure."

In September 2005, about a year after Muno found the magnetar, the object produced a burst that luckily came at a time when it was being heavily observed with several satellites, including the European Space Agency's X-ray satellite, XMM-Newton, and NASA's Swift X-ray and gamma-ray observatory. Just five days before the burst, Muno and his collaborators had been looking at the magnetar with XMM-Newton and saw it in the relatively calm state in which he had originally found it.

As most magnetars do, it produced a beam of X-ray light that, like the beam from a lighthouse, swept across Earth once every ten seconds. This allowed its rotational rate to be determined very precisely. The event that produced the burst also caused the magnetar to shine 100 times more brightly, created three separate beams that sweep past Earth where previously only one had existed, and sped up its rotation rate by about a thousandth of a second.

Muno says more work is required to understand what happened with the magnetar, because it is built of matter far denser than anything on Earth, and its composition is still a mystery.

However, it is possible to make educated guesses by extending theories developed to explain other neutron stars. The magnetic fields inside the neutron star are probably wound up, like a twisted spring. In a manner somewhat similar to plate tectonics here on Earth, as the magnetic fields unwind, they put stress on the outer crust. The crust would resist these stresses for a while, but would eventually fracture, producing a seismic event. The fractures would cause the magnetar's surface to shine brightly from multiple sources.

Also, there is reason to think that part of the interior of the neutron star is liquid and may be rotating faster than the crust. The seismic event could cause this fluid to become attached to the crust, so that the outer crust would speed up slightly.

"So we think the crust cracked," Muno says, adding that the observations are important for two reasons. "First, we have now seen another way in which these exotic objects dissipate their internal fields as they age.”

"Second, this event was only spotted because a team of us were concentrating hard on this newly discovered object," he adds. "The fact that we saw the event only a year after we discovered the magnetar implies that dozens more could be lurking in our Galaxy."

"If we find many more of these magnetars, we will have to re-evaluate our understanding of what happens when stars die," says Gianluca Israel, an Italian astronomer who is publishing a separate paper on the magnetar with his collaborators in the Astrophysical Journal.

Muno is lead author of a paper appearing this week in Monthly Notices of the Royal Astronomical Society.

Norbert Schartel | alfa
Further information:
http://www.esa.int/esaSC/SEMZR97DWZE_index_0.html

More articles from Physics and Astronomy:

nachricht Ultra-compact phase modulators based on graphene plasmons
27.06.2017 | ICFO-The Institute of Photonic Sciences

nachricht Smooth propagation of spin waves using gold
26.06.2017 | Toyohashi University of 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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>