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arXiv · 2611.03248

A Multi-messenger Study of the Cygnus bubble

Abhijit Roy·Giovanni Morlino·C Rishi·Jagdish C. Joshi·Soebur Razzaque·Neelam Panwar
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Abstract

We perform a comprehensive investigation of particle acceleration at the termination shocks of massive star clusters, with a particular focus on the Cygnus region. Building on the particle-acceleration model for cluster-driven winds, we use recently available spectral and spatial measurements of ultra-high-energy $γ$-rays from the Cygnus bubble to place stringent constraints on the physical conditions in the acceleration zone. By jointly modelling the observed $γ$-ray spectrum and spatial morphology, we derive quantitative limits on key parameters such as the maximum particle energy, acceleration efficiency, magnetic-field strength, and shock geometry, and assess their consistency with a hadronic origin of the emission. These data allow us to refine the target gas profiles within and around the bubble, thereby improving estimates of the expected hadronic $γ$-ray and neutrino fluxes. Using this revised gas model, we compute the neutrino emission associated with the Cygnus bubble and evaluate the statistical significance of a potential neutrino signal from this region for current and near-future high-energy neutrino observatories. Taken together, these results provide a more precise characterisation of the particle-acceleration environment at cluster termination shocks and help clarify the role of young massive star clusters as potential Galactic PeVatrons and contributors to the observed diffuse high-energy neutrino and $γ$-ray emissions.

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Abhijit Roy, Giovanni Morlino, C Rishi, Jagdish C. Joshi, Soebur Razzaque, Neelam Panwar. 2026-11-02. A Multi-messenger Study of the Cygnus bubble. https://arxiv.org/abs/2611.03248

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