On the hard $\gamma$-ray spectrum of the potential PeVatron supernova remnant G106.3+2.7

Abstract

The Tibet AS$\gamma$ experiment has measured $\gamma$-ray flux of supernova remnant G106.3+2.7 up to 100 TeV, suggesting it {being} potentially a "PeVatron". Challenge arises when the hadronic scenario requires a hard proton spectrum (with spectral index $\approx 1.8$), while {usual observations and numerical simulations prefer} a soft proton spectrum {(with spectral index $\ge 2$)}. In this paper, we explore an alternative scenario to explain the $\gamma$-ray spectrum of G106.3+2.7 within the current understanding of acceleration and escape processes. We consider that the cosmic ray {particles} are scattered by the turbulence driven via Bell instability. The resulting hadronic $\gamma$-ray spectrum is novel, dominating the contribution to the emission above 10\,TeV, and can explain the bizarre broadband spectrum of G106.3+2.7 in combination with leptonic emission from the remnant.

accepted by ApJ

References in corpus (12)

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Cited by in corpus (2)

• MAGIC observations provide compelling evidence of the hadronic multi-TeV emission from the putative PeVatron SNR G106.3+2.7
• A Possible Hadronic Origin of TeV Photon Emission from SNR G106.3+2.7