London, April 1: A new computer simulation has suggested that neutron stars can boast of topographical features such as plateaus or mountains, which could ripple the surrounding fabric of space, producing gravitational waves.

According to a report in New Scientist, Matthias Vigelius and Andrew Melatos from the University of Melbourne in Australia, developed the simulation.

The concept of gravitational waves has already been predicted by Albert Einstein's theory of general relativity, which determined that that the motion of slightly lopsided or asymmetrical objects should trigger these waves in space.

But so far detectors set up to capture the waves – such as LIGO (Laser Interferometer Gravitational-Wave Observatory) in the US and Virgo in Italy – have failed to find any sign of them.

Now, Vigelius and Melatos, through their computer simulation, provide new hope that detectable waves may be produced by some neutron stars.

Neutron stars are the cores left behind when relatively massive stars explode as supernovae. They are incredibly dense, packing about as much mass as the Sun into a sphere just 20 kilometres or so across, and some rotate hundreds of times per second.

Because of their extreme gravity and rotational speed, neutron stars could potentially make large ripples in the fabric of space – but only if their surfaces contain bumps or other imperfections.

Vigelius and Melatos found that massive, stable ‘mountains’ can grow on the surface of a neutron star using material stolen from an ordinary companion star.

In the first 3D computer simulation of this process, they found that the neutron star’s magnetic field channels this stolen matter to its magnetic poles, creating a mountain on each pole.

The magnetic field reinforces the mountains, preventing them from being flattened down completely by the star’s powerful gravity.

According to the new simulation, mountains with about as much mass as the planet Saturn can form and persist at each pole.

The matter pulled off the companion star would start out as a gas of protons and electrons. But under the high-pressure conditions at the neutron star’s surface, it would be transformed into a material made of pure neutrons.

As to how the mountains would look like up close, they would be very flattened compared to their counterparts on Earth.

“They would extend about 3 kilometres horizontally, but only rise to between 10 centimetres and 1 metre above the surrounding surface,” said Vigelius.

According to the researchers, these neutron star mountains would give off a very regular pattern of gravitational waves that would continue essentially indefinitely, making them easier to distinguish from random noise in the detectors. (ANI)