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arXiv · 2602.08940

Microquasar Remnants as Pevatrons Illuminating the Galactic Cosmic Ray Knee

Bing Theodore Zhang·Shiqi Yu
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Abstract

Microquasars are primary candidates for Galactic PeVatrons, yet their collective contribution to the cosmic ray (CR) ``knee" remains poorly understood. We investigate this contribution by simulating anisotropic diffusive propagation through the Galactic magnetic field. Our results demonstrate that spatial alignment and magnetic connectivity between source locations and the solar neighborhood govern the local flux: sources aligned with local magnetic field lines yield pronounced flux enhancements, whereas magnetically disconnected locations are strongly suppressed. We find that the characteristic proton bump near PeV is robust across random realizations of the Galactic microquasar remnant population, with as few as four nearby remnants accounting for 50\% of the observed PeV flux. Our findings suggest that the integrated history of microquasar remnants, governed by source temporal and spatial distribution and magnetic transport, naturally populates the observed CR ``knee''.

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Bing Theodore Zhang, Shiqi Yu. 2026-02-09. Microquasar Remnants as Pevatrons Illuminating the Galactic Cosmic Ray Knee. https://arxiv.org/abs/2602.08940

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