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arXiv · 2503.01172

Detection Prospects of Electromagnetic Signatures from OGLE-2011-BLG-0462

Shigeo S. Kimura·Lena Murchikova·Kailash C. Sahu
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Abstract

Stellar-mass isolated black holes (IsoBHs) wandering in interstellar medium (ISM) are expected to be abundant in our Galaxy. Recently, an IsoBH, OGLE-2011-BLG-0462, was unambiguously discovered using astrometric microlensing. We examine prospects for detecting electromagnetic signatures from an accretion flow surrounding the IsoBH. The accretion rate onto the IsoBH should be highly sub-Eddington, which leads to formation of a hot accretion flow. In this paper, we evaluate the detectability of electromagnetic signals from the hot accretion flows in two accretion states: magnetically arrested disk (MAD) and classical radiatively inefficient accretion flows (RIAFs). For the MAD scenario, we find that the optical, infrared, and X-ray signals can be detectable by the current best facilities, such as HST, JWST, and Chandra, if the IsoBH is in a warm neutral medium. In contrast, for the classical RIAF scenario, the optical and X-ray emissions are weaker than MAD scenario, leading to unobservable signals for a typical parameter set. Future follow-up observations of OGLE-2011-BLG-0462 will provide a good test for theories of accretion processes.

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Shigeo S. Kimura, Lena Murchikova, Kailash C. Sahu. 2025-06-12. Detection Prospects of Electromagnetic Signatures from OGLE-2011-BLG-0462. https://doi.org/10.3847/1538-4357%2Fadd52c

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