| Astrophysics (Index) | About |
The term direct collapse black hole (DCBH) refers to a black hole that formed through a single gravitational collapse, e.g., of a massive cloud. The term implies the collapsing material did not first live out a lifetime as a star. The concept is motivated by the existence of black holes more massive than expected, which need an explanation: The supermassive black holes (SMBHs) of observed distant quasars seem larger than possible, given the age of the universe viewed at that distance and the mechanism that should limit their accretion rate, i.e., the Eddington limit. One explanatory theory is that a SMBH might form in a single event that greatly exceeds the limit for a short time, achieving nearly all their observed mass at formation time. It is presumed this might have happened in the early universe and high redshift observation data is searched for evidence of already-too-massive SMBHs (e.g., active galactic nuclei) and evidence of such events.
An alternative theory of SMBHs posits the existence of some unknown, long-term way of exceeding the Eddington limit on accretion.
Intermediate-mass black holes (IMBHs) whose existence GW detections have confirmed, would also seem to be candidates for this type of scenario.