Galactic Isolated Stellar-Mass Black Holes with the Magnetospheric Spark Gap as Possible GeV-TeV Gamma-ray Unidentified Sources

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Kin, Koki, Kuze, Riku, Kimura, Shigeo S.
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909491122929664
author Kin, Koki
Kuze, Riku
Kimura, Shigeo S.
author_facet Kin, Koki
Kuze, Riku
Kimura, Shigeo S.
contents Billions of isolated stellar-mass black holes (IBHs) are thought to wander through the interstellar medium (ISM) in the Galaxy, yet only one has been detected. IBHs embedded in ISM would accrete gas via Bondi-Hoyle-Littleton accretion, and with efficient magnetic flux accumulation, the magnetosphere would be formed in the vicinity of IBHs. We explore the detectability of such IBHs through high-energy gamma rays from spark gaps in their magnetospheres based on our recent numerical simulation. The gap gamma rays can be bright at the GeV-TeV energies when IBHs are in the dense ISM. About $10^3$ and $10$ IBHs might be contained in unidentified objects of the $\textit{Fermi}$ Large Area Telescope and the High Energy Stereoscopic System, respectively. A future Galactic plane survey by the Cherenkov Telescope Array Observatory would lead to $\sim10^2$ detections. We also evaluate the combined gamma-ray emission of IBHs in the Galaxy and find that the IBHs may contribute to the Galactic diffuse gamma rays. IBHs will emit optical and X-ray photons from their accretion disk as counterparts, potentially useful for identifying candidates.
format Preprint
id arxiv_https___arxiv_org_abs_2502_09181
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Galactic Isolated Stellar-Mass Black Holes with the Magnetospheric Spark Gap as Possible GeV-TeV Gamma-ray Unidentified Sources
Kin, Koki
Kuze, Riku
Kimura, Shigeo S.
High Energy Astrophysical Phenomena
Billions of isolated stellar-mass black holes (IBHs) are thought to wander through the interstellar medium (ISM) in the Galaxy, yet only one has been detected. IBHs embedded in ISM would accrete gas via Bondi-Hoyle-Littleton accretion, and with efficient magnetic flux accumulation, the magnetosphere would be formed in the vicinity of IBHs. We explore the detectability of such IBHs through high-energy gamma rays from spark gaps in their magnetospheres based on our recent numerical simulation. The gap gamma rays can be bright at the GeV-TeV energies when IBHs are in the dense ISM. About $10^3$ and $10$ IBHs might be contained in unidentified objects of the $\textit{Fermi}$ Large Area Telescope and the High Energy Stereoscopic System, respectively. A future Galactic plane survey by the Cherenkov Telescope Array Observatory would lead to $\sim10^2$ detections. We also evaluate the combined gamma-ray emission of IBHs in the Galaxy and find that the IBHs may contribute to the Galactic diffuse gamma rays. IBHs will emit optical and X-ray photons from their accretion disk as counterparts, potentially useful for identifying candidates.
title Galactic Isolated Stellar-Mass Black Holes with the Magnetospheric Spark Gap as Possible GeV-TeV Gamma-ray Unidentified Sources
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2502.09181