Baffling quasar alignment hints at cosmic strings

[n2doc]

07 May 2010 by Anil Ananthaswamy


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.

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.

more

http://www.newscientist.com/article/mg20627593.900-baffling-quasar-alignment-hints-at-cosmic-strings.html

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