Featured Research

from universities, journals, and other organizations

'Glitch’ in pulsar ‘glitch’ theory

Date:
December 18, 2012
Source:
University of Southampton
Summary:
Researchers have called in to question a 40 year-old theory explaining the periodic speeding up or ‘glitching’ of pulsars. A pulsar is a highly magnetized rotating neutron star formed from the remains of a supernova. It emits a rotating beam of electromagnetic radiation, which can be detected by powerful telescopes when it sweeps past the Earth, rather like observing the beam of a lighthouse from a ship at sea. Pulsars rotate at extremely stable speeds, but occasionally they speed up in brief events described as ‘glitches’ or ‘spin-ups’. The prevailing theory is that these events arise as a rapidly spinning superfluid within the star transfers rotational energy to the star’s crust, the component that is tracked by observations. However, academics have used a mathematical model to disprove this.

Background: The Vela supernova remnant at optical wavelengths, with location of the Vela pulsar indicated. Inset: Artist's impression of the pulsar’s interior, and the interaction between superfluid vortices and the nuclei that make up the star’s crust.
Credit: CTIO/AURA/NSF

Researchers from the University of Southampton have called in to question a 40 year-old theory explaining the periodic speeding up or 'glitching' of pulsars.

A pulsar is a highly magnetised rotating neutron star formed from the remains of a supernova. It emits a rotating beam of electromagnetic radiation, which can be detected by powerful telescopes when it sweeps past the Earth, rather like observing the beam of a lighthouse from a ship at sea.

Pulsars rotate at extremely stable speeds, but occasionally they speed up in brief events described as 'glitches' or 'spin-ups'. The prevailing theory is that these events arise as a rapidly spinning superfluid within the star transfers rotational energy to the star's crust, the component that is tracked by observations. However, Southampton academics have used a mathematical model to disprove this.

Professor Nils Andersson explains: "Imagine the pulsar as a bowl of soup, with the bowl spinning at one speed and the soup spinning faster. Friction between the surface of the bowl and its contents, the soup, will cause the bowl to speed up. The more soup there is, the faster the bowl will be made to rotate.

"This analogy describes the concept behind the accepted theory of why pulsars suddenly increase speed or 'spin-up'. However, our research shows that these pulsar glitches are too large to be explained in this way. The amount of superfluid, or 'soup', available in the crust of a pulsar is too small to cause the kind of friction needed to create this effect."

Professor Andersson and Dr Wynn Ho from the University of Southampton used their calculations, in conjunction with data from radio telescopes and recent results from nuclear physics theory, to challenge current thinking on this subject.

The Southampton researchers have written a paper detailing their theory, produced in collaboration with Kostas Glampedakis at the Universidad de Murcia, Spain and Cristobal Espinoza at the University of Manchester.


Story Source:

The above story is based on materials provided by University of Southampton. Note: Materials may be edited for content and length.


Journal Reference:

  1. N. Andersson, K. Glampedakis, W. Ho, C. Espinoza. Pulsar Glitches: The Crust is not Enough. Physical Review Letters, 2012; 109 (24) DOI: 10.1103/PhysRevLett.109.241103

Cite This Page:

University of Southampton. "'Glitch’ in pulsar ‘glitch’ theory." ScienceDaily. ScienceDaily, 18 December 2012. <www.sciencedaily.com/releases/2012/12/121218111554.htm>.
University of Southampton. (2012, December 18). 'Glitch’ in pulsar ‘glitch’ theory. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2012/12/121218111554.htm
University of Southampton. "'Glitch’ in pulsar ‘glitch’ theory." ScienceDaily. www.sciencedaily.com/releases/2012/12/121218111554.htm (accessed July 29, 2014).

Share This




More Space & Time News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. Video provided by Newsy
Powered by NewsLook.com
NASA EDGE: OCO-2 Launch

NASA EDGE: OCO-2 Launch

NASA (July 25, 2014) NASA EDGE webcasts live from Vandenberg AFB for the launch of the Oribiting Carbon Observatory-2 (OCO) launch. Video provided by NASA
Powered by NewsLook.com
This Week @ NASA, July 25, 2014

This Week @ NASA, July 25, 2014

NASA (July 25, 2014) Apollo 11 celebration, Next Giant Leap anticipation, ISS astronauts appear in the House and more... Video provided by NASA
Powered by NewsLook.com
Space to Ground: Coming and Going

Space to Ground: Coming and Going

NASA (July 25, 2014) One station cargo ship leaves, another arrives, aquatic research and commercial spinoffs. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
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:
from the past week

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