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arXiv · 2609.31762

Radiative properties and optical appearance of a thin accretion disk around a charged-PFDM black hole

Taiyang Zhang·Zongyuan Qin·Qian Feng·Zheng-Wen Long
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Abstract

Accretion onto magnetically charged black holes in a perfect fluid dark matter (PFDM) background opens a new window for testing strong-field gravity. This paper investigates the radiative properties and optical appearance of a thin accretion disk surrounding a charged-PFDM black hole. We numerically compute the radiative energy flux, temperature distribution, and radiative efficiency, and employ a ray-tracing method to construct the direct images, secondary images, redshift distribution, and observed flux. By comparing with the Schwarzschild and pure PFDM cases, we find that the thin-disk efficiency of the charged-PFDM black hole lies between the two, with the magnetic charge partially counteracting the dark-matter-induced efficiency enhancement; for M87*, the efficiency is estimated to be 7\%--8\%. The optical appearance is predominantly governed by the PFDM parameter, while the magnetic charge plays only a marginal role. Larger inclination angles give rise to stronger Doppler asymmetry, producing the characteristic ``hat-like'' shape. These results provide falsifiable predictions for future high-resolution observations, such as those by ngEHT, to distinguish dark-matter environments from magnetic-charge effects.

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Taiyang Zhang, Zongyuan Qin, Qian Feng, Zheng-Wen Long. 2026-09-24. Radiative properties and optical appearance of a thin accretion disk around a charged-PFDM black hole. https://arxiv.org/abs/2609.31762

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