EMU Detection of a Large and Low Surface Brightness Galactic SNR G288.8-6.3

Miroslav D. Filipović; Shi Dai; Bojan Arbutina; Natasha Hurley-Walker; Robert Brose; Werner Becker; Hidetoshi Sano; Dejan Urošević; T. H. Jarrett; Andrew M. Hopkins; Rami Z. E. Alsaberi; R. Alsulami; Cristobal Bordiu; Brianna Ball; Filomena Bufano; Christopher Burger-Scheidlin; Evan Crawford; Jayanne English; Frank Haberl; Adriano Ingallinera; Anna D. Kapinska; Patrick J. Kavanagh; Bärbel S. Koribalski; Roland Kothes; Sanja Lazarević; Jonathan Mackey; Gavin Rowell; Denis Leahy; Sara Loru; Peter J. Macgregor; Luciano Nicastro; Ray P. Norris; Simone Riggi; Manami Sasaki; Milorad Stupar; Corrado Trigilio; Grazia Umana; Tessa Vernstrom; Branislav Vukotić

arXiv · 2308.08716

EMU Detection of a Large and Low Surface Brightness Galactic SNR G288.8-6.3

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Abstract

We present the serendipitous detection of a new Galactic Supernova Remnant (SNR), G288.8-6.3 using data from the Australian Square Kilometre Array Pathfinder (ASKAP)-Evolutionary Map of the Universe (EMU) survey. Using multi-frequency analysis, we confirm this object as an evolved Galactic SNR at high Galactic latitude with low radio surface brightness and typical SNR spectral index of $α= -0.41\pm0.12$. To determine the magnetic field strength in SNR G288.8-6.3, we present the first derivation of the equipartition formulae for SNRs with spectral indices $α>-0.5$. The angular size is $1.\!^\circ 8\times 1.\!^\circ 6$ $(107.\!^\prime 6 \times 98.\!^\prime 4)$ and we estimate that its intrinsic size is $\sim40$pc which implies a distance of $\sim1.3$kpc and a position of $\sim140$pc above the Galactic plane. This is one of the largest angular size and closest Galactic SNRs. Given its low radio surface brightness, we suggest that it is about 13000 years old.

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Miroslav D. Filipović, Shi Dai, Bojan Arbutina, Natasha Hurley-Walker, Robert Brose, Werner Becker, Hidetoshi Sano, Dejan Urošević, T. H. Jarrett, Andrew M. Hopkins, Rami Z. E. Alsaberi, R. Alsulami, Cristobal Bordiu, Brianna Ball, Filomena Bufano, Christopher Burger-Scheidlin, Evan Crawford, Jayanne English, Frank Haberl, Adriano Ingallinera, Anna D. Kapinska, Patrick J. Kavanagh, Bärbel S. Koribalski, Roland Kothes, Sanja Lazarević, Jonathan Mackey, Gavin Rowell, Denis Leahy, Sara Loru, Peter J. Macgregor, Luciano Nicastro, Ray P. Norris, Simone Riggi, Manami Sasaki, Milorad Stupar, Corrado Trigilio, Grazia Umana, Tessa Vernstrom, Branislav Vukotić. 2023-08-17. EMU Detection of a Large and Low Surface Brightness Galactic SNR G288.8-6.3. https://arxiv.org/abs/2308.08716

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