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arXiv · 2601.10968

Radiative Cooling Effects on Plasmoid Formation in Black Hole Accretion Flows with Multiple Magnetic Loops

Jing-Ze Xia·Hong-Xuan Jiang·Yosuke Mizuno·Antonios Nathanail·M. Christian Fromm
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Abstract

We investigate the influence of radiative cooling on plasmoid formation in black hole accretion flows using 2D and 3D two-temperature GRMHD simulations with multi-loop magnetic fields. Our results show that radiative cooling suppresses the transition to a MAD state by reducing magnetic flux accumulation near the horizon, modifies the disk structure via lower electron temperatures and increased equatorial density, and alters reconnection properties:compressing current sheets, shortening plasmoid lifetimes, and increasing their frequency. We also find enhanced negative energy-at-infinity density in plasmoids near the ergosphere. These findings indicate that radiative cooling critically shapes both large scale accretion dynamics and small-scale reconnection phenomena, potentially modulating black hole energy extraction through reconnection-driven Penrose processes.

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Jing-Ze Xia, Hong-Xuan Jiang, Yosuke Mizuno, Antonios Nathanail, M. Christian Fromm. 2026-01-16. Radiative Cooling Effects on Plasmoid Formation in Black Hole Accretion Flows with Multiple Magnetic Loops. https://doi.org/10.1051/0004-6361%2F202557948

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