Overview
Research indicates that black holes across a wide range of masses may adhere to a uniform principle governing the emission of powerful jets. This principle appears to link jet activation to a specific reduction in the black hole's accretion rate, suggesting a common physical mechanism despite vast differences in scale.
Findings
Scientists have identified evidence suggesting that supermassive black holes (SMBHs) and significantly smaller black holes within the Milky Way exhibit a shared operational rule concerning powerful jet production. Specifically, the re-activation of jets from SMBHs, particularly those observed following the disruption of a star, was found to occur when the black hole's feeding rate decreased to approximately 2% of the Eddington limit. This observed threshold for SMBHs aligns with the known feeding rate threshold that triggers jet emission from much smaller black holes located in the Milky Way.
The temporal dynamics observed in SMBHs post-stellar disruption include an initial period of jet production soon after the star's destruction. Subsequently, these SMBHs can re-initiate jet activity hundreds or thousands of days later. This delayed re-ignition correlates with the feeding rate dropping to the aforementioned 2% Eddington limit.
Why This Matters
The identification of a potentially universal rule for jet production across black holes of vastly different sizes implies a fundamental, scale-independent physical process. This suggests that the underlying mechanisms driving jet formation might be consistent from stellar-mass black holes to supermassive black holes at galactic centers.