Monday, November 10, 2014

ALMA and ATCA Astronomers dissect the remnants of a supernova

Simulated still showing components of Supernova Remnant 1987A

Credit: The International Centre for Radio Astronomy Research (ICRAR)

In research published today in the Astrophysical Journal, an Australian led team of astronomers has used radio telescopes in Australia and Chile to see inside the remains of a supernova.

The supernova, known as SN1987A, was first seen by observers in the Southern Hemisphere in 1987 when a giant star suddenly exploded at the edge of a nearby dwarf galaxy called the Large Magellanic Cloud.

In the two and a half decades since then the remnant of Supernova 1987A has continued to be a focus for researchers the world over, providing a wealth of information about one of the Universe's most extreme events.

PhD Candidate Giovanna Zanardo at The University of Western Australia node of the International Centre for Radio Astronomy Research (ICRAR) led the team that used the Atacama Large Millimetre/submillimeter Array (ALMA) in Chile's Atacama Desert and the Australia Telescope Compact Array (ATCA) in New South Wales to observe the remnant at wavelengths spanning the radio to the far infrared.

"By combining observations from the two telescopes we've been able to distinguish radiation being emitted by the supernova's expanding shock wave from the radiation caused by dust forming in the inner regions of the remnant," said Zanardo.

A panel of images showing different views of Supernova 1987A. 

Left Panel: SNR1987A as seen by the Hubble Space Telescope in 2010. 

Middle Panel: SNR1987A as seen by the ATCA in New South Wales and the ALMA in Chile. 

Right Panel: A computer generated visualisation of the remnant showing the possible location of a Pulsar. 

Credit: ATCA & ALMA Observations & data - G. Zanardo et al. / HST Image: NASA, ESA, K. France (University of Colorado, Boulder), P. Challis and R. Kirshner (Harvard-Smithsonian Center for Astrophysics)

"This is important because it means we're able to separate out the different types of emission we're seeing and look for signs of a new object which may have formed when the star's core collapsed. It's like doing a forensic investigation into the death of a star."

"Our observations with the ATCA and ALMA radio telescopes have shown signs of something never seen before, located at the centre or the remnant. It could be a pulsar wind nebula, driven by the spinning neutron star, or pulsar, which astronomers have been searching for since 1987."

"It's amazing that only now, with large telescopes like ALMA and the upgraded ATCA, we can peek through the bulk of debris ejected when the star exploded and see what's hiding underneath."

More research published recently in the Astrophysical Journal also attempts to shine a light on another long-standing mystery surrounding the supernova remnant.

Since 1992 the radio emission from one side of the remnant has appeared 'brighter' than the other.

More information: 'Spectral and Morphological Analysis of the Remnant of Supernova 1987a with ALMA & ATCA' G. Zanardo, L. Staveley-Smith, R. Indebetouw et al. Astrophysical Journal November 10th, 2014: and

'Multi-dimensional simulations of the expanding supernova remnant SN 1987a' T.M Potter, L Staveley-Smith, B. Reville et al. Astrophysical Journal October 20th, 20144: and

No comments:

Post a Comment