Feeds

Cosmic blast mystery solved in neutron star's intense death throes

'As if millions of voices suddenly cried out in terror and were suddenly silenced'

  • alert
  • submit to reddit

Intelligent flash storage arrays

A pair of European astrophysicists believe they've solved the mystery of exceedingly bright, never-repeated flashes of radio waves that come to us from the distant past.

The source of those brief, intense flashes can be defined in two ways, depending upon whether you'd prefer to look at the event as a death or a birth.

"We suggest that a fast radio burst represents the final signal of a supramassive rotating neutron star that collapses to a black hole due to magnetic braking," write Heino Falcke of Radboud University in Nijmegen, the Netherlands, and Luciano Rezzolla of the Albert Einstein Institute in Potsdam, Germany in their paper (preprint, PDF) "Fast radio bursts: the last sign of supramassive neutron stars" published in this week's edition of Science.

Neutron stars are ludicrously dense objects. According to the press release outlining Falcke and Rezzolla's findings, "They are the size of a small city but have up to two times the mass of our Sun."

As you might assume, something that massive has an upper limit on its mass, otherwise it would collapse in upon itself and become a black hole – and you'd be right. There are, however, neutron stars that are larger than the critical mass of about two solar masses, but that manage to keep from falling in on themselves due to their high rotational velocity.

A supramassive neutron star on its way to becoming a 'blitzar'

Cleaning up the neighborhood in preparation from metamorphosis from neutron star to black hole

If an overweight neutron star is spinning fast enough, the centrifugal forces that are generated by that speedy rotation can counterbalance the forces of gravity, and keep the star from falling in on itself for millions of years – but not forever.

The reason for their inevitable doom is that neutron stars also have extremely powerful magnetic fields that radiate outward from them. "Over time," Falcke and Rezzolla write, "magnetic braking would clear out the immediate environment of the star and slow it down." And when it slows down sufficiently, the centrifugal forces diminish to an extent that gravity will achieve its inevitable victory.

Normally when a star collapses into a black hole, there is also a burst of optical and gamma-ray radiation. Not so in this scenario, seeing as that the rotating neutron star's magnetic field has already cleaned out the neighborhood, and that the event horizon of the black hole quickly engulfs the surface of the neutron star.

"All the neutron star has left is its magnetic field, but black holes cannot sustain magnetic fields, so the collapsing star has to get rid of them," explains Falcke. "When the black hole forms, the magnetic fields will be cut off from the star and snap like rubber bands," and that snap is what produces the immense, one-time radio flash that has been observed.

"All other signals you normally would expect – gamma rays, x-rays – simply disappear behind the event horizon of the black hole," says Flacke.

Falcke and Rezzolla have dubbed these objects blitzars – "blitz" being German for "flash" or "lightning". "A blitzar," Rezzola writes, "is at the same time the farewell signal of a dying neutron star and the first message from a newly born black hole." ®

Intelligent flash storage arrays

More from The Register

next story
MARS NEEDS WOMEN, claims NASA pseudo 'naut: They eat less
'Some might find this idea offensive' boffin admits
Boffins who stare at goats: I do believe they’re SHRINKING
Alpine chamois being squashed by global warming
Comet Siding Spring revealed as flying molehill
Hiding from this space pimple isn't going to do humanity's reputation any good
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
LONG ARM of the SAUR: Brachially gifted dino bone conundrum solved
Deinocheirus mirificus was a bit of a knuckle dragger
No sail: NASA spikes Sunjammer
'Solar sail' demonstrator project binned
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
prev story

Whitepapers

Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.