Researchers used a radio telescope to look inside the remains of a supernova and gain insight into one of the most extreme events that exists in our universe.
The supernova, dubbed SN1987A, was first spotted by observers in 1987 when a giant star exploded on the edge of the Large Magellanic Cloud dwarf galaxy, the International Centre for Radio Astronomy Research (ICRAR) reported. To make their findings the researchers used the Atacama Large Millimetre/submillimeter Array (ALMA) and the Australia Telescope Compact Array (ATCA).
"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 Giovanna Zanardo of the International Centre for Radio Astronomy Research (ICRAR).
The research allowed the scientists to separate the different types of emissions seen in the observations and locate a mysterious object that is believed to have formed when the star collapsed.
"Our observations with the ATCA and ALMA radio telescopes have shown signs of something never seen before, located at the [center] 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," said Toby Potter, another researcher from ICRAR's UWA node.
Another puzzling aspect of the object was that one side was much brighter than the other; in order to solve this mystery the researchers developed a detailed three-dimensional simulation of the shockwave emitted by the expanding supernova. The model revealed the eastern side of the shock front expanded more quickly than the other side, causing it to emit more radio emissions. The effect became even stronger as the shock collided into the equatorial ring because the "lop-sidedness" was reduced and may have even swapped sides.
"The fact that the model matches the observations so well means that we now have a good handle on the physics of the expanding remnant and are beginning to understand the composition of the environment surrounding the supernova -- which is a big piece of the puzzle solved in terms of how the remnant of SN1987A formed," Potter said.
The findings were published Nov. 10 in the Astrophysical Journal.
