New research suggests previous assumptions regarding the growth and nature of black holes were incorrect, Becky Smethurst of the University of Oxford said.
This shift in understanding matters because it challenges the long-held belief that black holes behave as simple vacuum cleaners. By rethinking how these objects form and interact with their surroundings, scientists may finally solve the puzzle of how some black holes reach billions of solar masses.
At the center of the Milky Way lies Sagittarius A*. This black hole has a mass 4.3 million times that of the Sun [1]. While this scale is immense, it is modest when compared to other super-massive black holes found in different galaxies.
Some of these cosmic giants reach up to 40 billion times the mass of the Sun [1]. The vast difference between Sagittarius A* and these larger entities suggests that the growth process is more complex than earlier models indicated.
Earlier theories often portrayed black holes as dense objects that simply suck up everything in their path. However, new observations and models suggest they are not vacuum cleaners at all [2]. This contradiction highlights a gap in previous physics models regarding how matter is actually consumed, and how mass is accumulated over time.
Scientists are now focusing on why some black holes grow to such extreme proportions while others remain relatively small. The discrepancy between the Milky Way's center and the largest known black holes indicates that the environment and specific formation triggers play a more significant role than previously understood.
“Black holes are not vacuum cleaners at all.”
The realization that the Milky Way's central black hole is relatively small compared to the largest known super-massive black holes forces a recalibration of galactic evolution models. If black holes do not simply 'vacuum' all nearby matter, their growth must depend on specific, perhaps rarer, cosmic conditions, suggesting that the history of our own galaxy may be atypical compared to the most massive systems in the universe.
