New supernova remnant discovered by ASKAP

An international team of astronomers has accidentally discovered a new Galactic Supernova Remnant (SNR) named SNR G288.8-6.3 using the Australian Square Kilometer Array Pathfinder (ASKAP). The discovery was announced in an article published on August 17th on the preprint server arXiv. The SNR is a diffusion expansion structure resulting from a supernova explosion. They contain ejecta swollen by the explosion and other interstellar material swept away by the passage of the exploding star’s shock wave. Supernova remnants play an important role in the evolution of galaxies, such as scattering heavy elements produced in supernova explosions and providing the energy needed to heat the interstellar medium, making supernova remnants important to astronomers. Research is important. SNR is also believed to be involved in the acceleration of galactic cosmic rays. Now, a group of astronomers led by Miroslav D. Filipovich of Western Sydney University in Australia have reported the discovery of a new SNR nearby. The discovery was made as part of the ASKAP Evolutionary Map of the Universe (EMU) survey using 36 of his ASKAP antennas with a center frequency of 943.4 MHz and a bandwidth of 288 MHz. “A new ASKAP-EMU survey stumbled upon a large object classified as a new galaxy SNR G288.8-6.3,” the researchers wrote in their paper.

SNR G288.8-6.3 has a characteristic size of about 130 light-years and a spectral index of -0.41, which is common for known SNRs. The remnant is about 4,200 light years from Earth and about 456 light years above the galactic plane. Therefore, SNR G288.8–6.3 turns out to be one of the largest and closest galactic supernova remnants. The spectral index of SNR G288.8-6.3 suggests that this remnant represents an evolutionarily advanced SNR population in the late adiabatic or radiative phase of evolution. In addition, the radio surface brightness of SNR G288.8–6.3 is relatively low, which, together with other characteristics, indicates an age of about 13,000 years. According to this paper, the collisional compaction of the magnetic field at SNR G288.8-6.3 is sufficient to generate a magnetic field large enough to explain the synchrotron radiation of the SNR. Based on a study of neutral atomic hydrogen (HI), the astronomers also found a cavity-like distribution within the wreckage and possible evidence of shock-cloud interactions. In summary, the authors of this article propose a more detailed polarimetry and multi-frequency observation of the G288.8–6.3 SNR to gain further insight into the nature of this newly discovered and interesting SNR.

Source: arXiv (2023). DOI: 10.48550/arxiv.2308.08716