A new supernova remnant has been detected using ASKAP

Using the Australian Square Kilometer Pathfinder Array (ASKAP), an international team of astronomers serendipitously discovered the remnants of a new galactic supernova (SNR), designated SNR G288.8–6.3. This finding was published in a research paper posted Aug. 17 on a preprint server arXiv.

SNRs are diffuse and expanding structures resulting from a supernova explosion. They contain ejecta, expanding from the explosion, and other interstellar material swept away by the passing shock wave from the exploding star.

Studies of supernova remnants are important to astronomers, as they play a key role in the evolution of galaxies, scattering heavy elements from the supernova explosion and providing the energy needed to heat the interstellar medium. SNRs are also thought to be responsible for accelerating galactic cosmic rays.

Now, a group of astronomers led by Miroslav D. Filipovic of Western Sydney University in Australia announced the discovery of a new relative SNR. The discovery was made using 36 ASKAP antennas with a center frequency of 943.4 MHz and a bandwidth of 288 MHz, as part of the ASKAP-Evolutionary Map of the Universe (EMU) survey.

“We serendipitously found a large-scale object in our new ASKAP-EMU survey, which we classify as new Galactic SNR G288.8–6.3,” the researchers wrote in their paper.

SNR G288.8–6.3 has a size of about 130 light-years across and a spectral index of -0.41, which is typical of known SNRs. The remnants lie about 4,200 light-years from Earth, and lie about 456 light-years above the plane of the galaxy. So it turns out that SNR G288.8–6.3 is one of the largest and closest supernova remnants in the galaxy.

The spectral index of SNR G288.8–6.3 indicates that this remnant represents an advanced evolutionary SNR population in the late adiabatic or in the radiative stage of development. Furthermore, SNR G288.8–6.3 has a relatively low radiosurface brightness, which, among other properties, indicates an age of about 13,000 years.

According to the paper, the magnetic field shock pressure in SNR G288.8–6.3 is sufficient to produce magnetic fields large enough to explain the synchrotron emission of the SNRs. Furthermore, based on a study of neutral atomic hydrogen (HI), astronomers have found a cavity-like distribution and possible evidence of shock-cloud interaction in this remnant.

To summarize the results, the paper’s authors propose further in-depth polarization and multi-frequency observations of the G288.8–6.3 SNR in order to gain more insights into the intriguing nature of the newly discovered SNR.

“In-depth, multi-frequency polarization studies will enhance our knowledge of this galactic body of large angular size,” the researchers concluded.

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