Baffling quasar alignment hints at cosmic strings | Space Discussions and Theories | Forum

A A A
Avatar

Please consider registering
guest

sp_LogInOut Log In sp_Registration Register

Register | Lost password?
Advanced Search

— Forum Scope —






— Match —





— Forum Options —





Minimum search word length is 3 characters - maximum search word length is 84 characters

sp_Feed Topic RSS sp_TopicIcon
Baffling quasar alignment hints at cosmic strings
May 8, 2010
12:51 am
Avatar
sandra
Member
Members
Forum Posts: 3858
Member Since:
December 4, 2009
sp_UserOfflineSmall Offline

Baffling quasar alignment hints at cosmic strings
07 May 2010 by Anil Ananthaswamy
Magazine issue 2759. Subscribe and save
For similar stories, visit the Cosmology Topic Guide
SOMETHING has made neighbouring quasars in the distant universe point in a similar direction when their orientations ought to be random. Could this be the signature of cosmic strings - gigantic kinks in the fabric of space-time?

In 2005, Damien Hutsemekers at the University of Liège, Belgium, and colleagues reported an unusual effect in observations of 355 quasars. They found that light from these quasars tended to be polarised, with the electromagnetic oscillations confined to a particular plane that can be described by a polarisation vector. Though there is no obvious reason to think these vectors should be oriented in a special way from one quasar to the next, Hutsemekers's team found that the orientations were not random. If they took any two adjacent quasars, the polarisation vectors pointed in much the same direction.

If they looked at any two adjacent quasars, the light from each was polarised in much the same direction
What's more, as the team looked at ever more distant quasars, they saw this vector rotate by about 30 degrees with every 3.26 billion light years from Earth. The vector turned clockwise when they looked in the direction of the north galactic pole of the Milky Way and anticlockwise looking towards the south pole (arxiv.org/abs/astro-ph/0507274v1).

Last year, the team showed that the direction of the polarisation vector is correlated with the axis of rotation of the quasar itself. That means that adjacent quasars tend to have roughly the same orientation - again, not something anyone would have expected to see.

Now, Robert Poltis and Dejan Stojkovic of the State University of New York in Buffalo say they have an explanation. It's all down to events that occurred about 10-12 seconds after the big bang. At that time the universe went through a phase transition, causing the electroweak force to separate into the electromagnetic force and the weak nuclear force. The standard model of particle physics suggests that this would also have resulted in the formation of cosmic strings, which are topological defects in the fabric of space-time and can take the form of giant loops.

Cosmic strings can cause magnetic fields to form along their lengths, says Poltis. The strings are unstable and quickly decay, but the magnetic fields remain and would have become stretched to cosmological scales as the universe expanded.

Poltis and Stojkovic modelled how two giant loops of magnetic field lines could affect galaxies as they formed. A proto-galaxy contains charged particles - electrons and hydrogen ions - which acquire angular momentum from the magnetic field. The net effect is that the proto-galaxy acquires an overall angular momentum, aligning its axis in a certain direction. Two neighbouring proto-galaxies forming in the vicinity of the same magnetic field would end up with their axes pointing in the same direction.

The researchers also showed how the twisting of the magnetic field lines on cosmic scales could cause the axes of quasars to rotate the further out you look (arxiv.org/abs/1004.2704).

"This explanation can indeed reproduce our observations quite well, even the possible rotation of the polarisation angle," says Hutsemekers. "Moreover, the possibility that the imprint of strings can be detected through the study of galaxy or quasar orientations is exciting."
http://www.newscientist.com/article/mg2 ... rings.html

“Living backwards!” Alice repeated in great
astonishment. “I never heard of such a thing!”
“—but there’s one great advantage in it, that one’s
memory works both ways.”
— Lewis Carroll, Through the Looking-Glass

Forum Timezone: America/Los_Angeles

Most Users Ever Online: 288

Currently Online:
57 Guest(s)

Currently Browsing this Page:
1 Guest(s)

Top Posters:

greeney2: 10236

bionic: 9870

at1with0: 9243

Lashmar: 5289

tigger: 4576

rath: 4297

DIss0n80r: 4161

sandra: 3858

frrostedman: 3815

Wing-Zero: 3278

Member Stats:

Guest Posters: 2

Members: 24082

Moderators: 0

Admins: 2

Forum Stats:

Groups: 8

Forums: 31

Topics: 8717

Posts: 123449

Newest Members:

Boadicea, hoangnganvy1993, D S, PDonnelly, Viatorem, Sharon, mack robine, Observer

Administrators: John Greenewald: 579, blackvault: 1776