Featured Research

from universities, journals, and other organizations

Largest magnetic fields in the universe

Date:
July 26, 2013
Source:
Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI)
Summary:
Numerical simulations show for the first time the occurrence of an instability in the interior of neutron stars that can lead to gigantic magnetic fields, possibly triggering one of the most dramatic explosions observed in the Universe.

An instability triggered in the interior of a hypermassive neutron star can lead to gigantic magnetic fields before the star collapses to a black hole.
Credit: Max Planck Institute for Gravitational Physics/D. Siegel

Numerical simulations by AEI scientists show for the first time the occurrence of an instability in the interior of neutron stars that can lead to gigantic magnetic fields, possibly triggering one of the most dramatic explosions observed in the Universe.

Related Articles


An ultra-dense ("hypermassive") neutron star is formed when two neutron stars in a binary system finally merge. Its short life ends with the catastrophic collapse to a black hole, possibly powering a short gamma-ray burst, one of the brightest explosions observed in the universe. Short gamma-ray bursts as observed with satellites like XMM Newton, Fermi or Swift release within a second the same amount of energy as our Galaxy in one year. It has been speculated for a long time that enormous magnetic field strengths, possibly higher than what has been observed in any known astrophysical system, are a key ingredient in explaining such emission. Scientists at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) have now succeeded in simulating a mechanism which could produce such strong magnetic fields prior to the collapse to a black hole.

How can such ultra-high magnetic fields -- stronger than ten or hundred million billion times Earth's magnetic field -- be generated from the much lower initial neutron star magnetic fields?

This could be explained by a phenomenon that can be triggered in a differentially rotating plasma in the presence of magnetic fields: neighbouring plasma layers, which rotate at different speeds, "rub against each other," eventually setting the plasma into turbulent motion. In this process called magnetorotational instability magnetic fields can be strongly amplified. This mechanism is known to play an important role in many astrophysical systems such as accretion disks and core-collapse supernovae. It had been speculated for a long time that magnetohydrodynamic instabilities in the interior of hypermassive neutron stars could bring about the necessary magnetic field amplification. The actual demonstration that this is possible has only now been achieved with the present numerical simulations.

The scientists of the Gravitational Wave Modelling Group at the AEI simulated a hypermassive neutron star with an initially ordered ("poloidal") magnetic field, whose structure is subsequently made more complex by the star's rotation. Since the star is dynamically unstable, it eventually collapses to a black hole surrounded by a cloud of matter, until the latter is swallowed by the black hole.

These simulations have unambiguously shown the presence of an exponentially rapid amplification mechanism in the stellar interior -- the magnetorotational instability. This mechanism has so far remained essentially unexplored under the extreme conditions of ultra-strong gravity as found in the interior of hypermassive neutron stars. This is because the physical conditions in the interior of these stars are extremely challenging.

The discovery is interesting for at least two reasons. First, it shows for the first time unambiguously the development of the magnetorotational instability in the framework of Einstein's theory of general relativity, in which there exist no analytical criteria to date to predict the instability. Second, this discovery can have a profound astrophysical impact, supporting the idea that ultra strong magnetic fields can be the key ingredient in explaining the huge amount of energy released by short gamma-ray bursts.


Story Source:

The above story is based on materials provided by Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI). Note: Materials may be edited for content and length.


Journal Reference:

  1. Daniel M. Siegel, Riccardo Ciolfi, Abraham I. Harte, Luciano Rezzolla. Magnetorotational instability in relativistic hypermassive neutron stars. Physical Review D, 2013; 87 (12) DOI: 10.1103/PhysRevD.87.121302

Cite This Page:

Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI). "Largest magnetic fields in the universe." ScienceDaily. ScienceDaily, 26 July 2013. <www.sciencedaily.com/releases/2013/07/130726043406.htm>.
Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI). (2013, July 26). Largest magnetic fields in the universe. ScienceDaily. Retrieved March 29, 2015 from www.sciencedaily.com/releases/2013/07/130726043406.htm
Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI). "Largest magnetic fields in the universe." ScienceDaily. www.sciencedaily.com/releases/2013/07/130726043406.htm (accessed March 29, 2015).

Share This


More From ScienceDaily



More Space & Time News

Sunday, March 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

What NASA Wants To Learn From Its 'Year In Space' Tests

What NASA Wants To Learn From Its 'Year In Space' Tests

Newsy (Mar. 28, 2015) Astronaut Scott Kelly and cosmonaut Mikhail Kornienko will spend a year in space running tests on human physiology and psychology. Video provided by Newsy
Powered by NewsLook.com
Crew Starts One-Year Space Mission

Crew Starts One-Year Space Mission

Reuters - News Video Online (Mar. 28, 2015) Russian-U.S. crew arrives safely at the International Space Station for the start of a ground-breaking year-long stay. Paul Chapman reports. Video provided by Reuters
Powered by NewsLook.com
Why So Many People Think NASA's Asteroid Mission Is A Waste

Why So Many People Think NASA's Asteroid Mission Is A Waste

Newsy (Mar. 27, 2015) The Asteroid Retrieval Mission announced this week bears little resemblance to its grand beginnings. Even NASA scientists are asking, "Why bother?" Video provided by Newsy
Powered by NewsLook.com
Space Station Crew Docks Safely

Space Station Crew Docks Safely

Reuters - News Video Online (Mar. 27, 2015) NASA TV footage shows the successful docking of a Russian Soyuz craft to the International Space Station for a year-long mission. Rough cut (no reporter narration). Video provided by Reuters
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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