Astronomers affiliated with the Supernova Legacy Survey (SNLS) have discovered two of the brightest and most distant supernovae ever recorded, 10 billion light-years away and a hundred times more luminous than a normal supernova.
These newly discovered supernovae are especially puzzling because the mechanism that powers most of them — the collapse of a giant star to a black hole or normal neutron star — cannot explain their extreme luminosity.
Discovered in 2006 and 2007, the supernovae were so unusual that astronomers initially could not figure out what they were or even determine their distances from Earth.
One of the newly discovered supernovae, named SNLS-06D4eu, is the most distant and possibly the most luminous member of an emerging class of explosions called superluminous supernovae. These new discoveries belong to a special subclass of superluminous supernovae that have no hydrogen.
The new study finds that the supernovae are likely powered by the creation of a magnetar, an extraordinarily magnetized neutron star spinning hundreds of times per second.
Magnetars have the mass of the sun packed into a star the size of a city and have magnetic fields a hundred trillion times that of the Earth.
Co-author Daniel Kasen from UC Berkeley and Lawrence Berkeley National Lab created models of the supernova that explained the data as the explosion of a star only a few times the size of the sun and rich in carbon and oxygen.
The findings have been published in the Astrophysical Journal.
--ANI (Posted on 19-12-2013)