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arXiv · 2410.02119

Astroparticles from X-ray Binary Coronae

Ke Fang·Francis Halzen·Sebastian Heinz·John S. Gallagher
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Abstract

The recent observation of high-energy neutrinos from the Galactic plane implies an abundant population of hadronic cosmic-ray sources in the Milky Way. We explore the role of the coronae of accreting stellar-mass black holes as such astroparticle emitters. We show that the particle acceleration and interaction timescales in the coronal region are tied to the compactness of the X-ray source. Thus, neutrino emission processes may similarly happen in the cores of active galactic nuclei and black hole X-ray binaries (XRB), despite of their drastically different masses and physical sizes. We apply the model to the well-measured XRB Cygnus X-1 and find that the cascaded gamma rays accompanying the neutrino emission naturally explain the GeV emission that only presents during the source's hard state, while the state-averaged gamma-ray emission explains the LHAASO observation above 20 TeV. We show that XRB coronae could contribute significantly to the Galactic cosmic-ray and Galactic plane neutrino fluxes. Our model predicts variable high-energy neutrino emission from bright Galactic XRBs that may be observed by IceCube and future neutrino observatories.

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Ke Fang, Francis Halzen, Sebastian Heinz, John S. Gallagher. 2024-10-03. Astroparticles from X-ray Binary Coronae. https://doi.org/10.3847/2041-8213%2Fad887b

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