April 2, 2013
First High-Resolution Radio Images Of Supernova 1987A Released
Lawrence LeBlond for redOrbit.com - Your Universe Online
An observation of the Large Magellanic Cloud (LMC) in February of 1987 left astronomers thinking they had discovered the beginnings of a new star. However, what they had witnessed was the end of one of the brightest supernovae seen from Earth since the invention of the telescope some 400 years earlier. And in the two-plus decades since the discovery of the remnant Supernova 1987A, researchers have continued their gaze on one of the Universe´s most extreme events.
Now, more than 25 years after astronomers first witnessed the “death throws” of the giant star in the LMC dwarf galaxy, a team of researchers led by the International Center for Radio Astronomy Research (ICRAR) have succeeded in making the highest resolution radio images of the expanding supernova remnant at millimeter wavelengths.
The team of astronomers, hailing from Australia and Hong Kong, used Australia´s Telescope Compact Array, CSIRO Radio Telescope and the Hubble Space Telescope to make their detailed observations. A paper on the research was published in the Astrophysical Journal yesterday.
"Imaging distant astronomical objects like this at wavelengths less than 1 centimeter demands the most stable atmospheric conditions. For this telescope these are usually only possible during cooler winter conditions but even then, the humidity and low elevation of the site makes things very challenging," said lead author, Dr Giovanna Zanardo of ICRAR, a joint venture of Curtin University and The University of Western Australia (UWA) in Perth.
Using the CSIRO radio telescope, the team was able to make detailed daytime observations, peering through gas and dust to see the inner workings of the supernova remnant.
"Supernova remnants are like natural particle accelerators, the radio emission we observe comes from electrons spiralling along the magnetic field lines and emitting photons every time they turn. The higher the resolution of the images the more we can learn about the structure of this object," said Professor Lister Staveley-Smith, Deputy Director of ICRAR and CAASTRO, the Centre for All-sky Astrophysics.
By studying the evolution of the massive star into a supernova remnant the team gained invaluable insight into the dynamics of the massive explosions and the interaction of the blast wave with the surrounding medium.
"Not only have we been able to analyze the morphology of Supernova 1987A through our high resolution imaging, we have compared it to X-ray and optical data in order to model its likely history," Professor Bryan Gaensler, Director of CAASTRO at the University of Sydney, said in a statement.
The team believes a pulsar wind nebula or other anomaly is sitting in the center of the radio emission, which would imply the supernova explosion did not make the star collapse into a black hole. The astronomers plan to observe the remnant further, peering deeper into the core to see if their suspicions are correct.