Description
Isolated stellar-mass black holes traversing dense regions of the interstellar medium, such as molecular clouds, are expected to accrete ambient gas. This accretion process can ionize surrounding gas, carving out a low-density ionized cavity within the cloud. The accreting black hole which possesses an accretion disc and a jet can further interacts with the cloud. Relativistic plasma from the jet interacts with cloud materials outside the cavity, triggering hadronic and leptonic interactions that can generate electromagnetic waves of different wavelengths such as high-energy gamma rays and X-rays. These processes may also contribute to the energetic particle populations within molecular clouds and serve as a potential source of cosmic rays. In this study, we investigate the observational signatures of isolated stellar-mass black holes accreting within molecular clouds. We consider two representative scenarios: (1) a black hole fully embedded inside a cloud and (2) a black hole partially embedded at the cloud’s boundary, corresponding to a case which the black hole is entering or exiting the cloud. We consider the accretion process, ionization sphere, and jet-cloud interactions in our model. We explore the resulting multi-wavelength emissions, the detectability of these systems, and the effects on star formations.
