Accretion onto Black Holes and Neutron Stars [chapter]

Norbert Straumann
1984 General Relativity and Relativistic Astrophysics  
A black hole is a region of space in which the matter is so compact that nothing can escape from it, not even light; the "surface" of a black hole, inside of which nothing can escape, is called an event horizon. The matter that forms a black hole is crushed out of existence. Just as the Cheshire Cat disappeared and left only its smile behind, a black hole represents matter that leaves only its gravity behind. Black holes are usually formed when an extremely massive star dies in a supernova.
more » ... in a supernova. However, some people think small black holes were formed during the Big Bang, and that the resulting "mini black holes" may be in great abundance in our galaxy. In reality, it is known that this limit can be violated, due to non-spherical geometry or various kinds of instabilities. Nevertheless, the Eddington limit remains an important reference point, and many of the details of how accretion proceeds above this limit remain unclear [Gregory B. Poole Chris Blake, David Parkinson, 2012]. Understanding how this so-called super-Eddington accretion occurs is of clear cosmological importance, since it potentially governs the growth of the first supermassive black holes (SMBHs) and the impact this growth would have had on their host galaxies and the epoch of reionization, as well as improving our understanding of accretion physics more generally.
doi:10.1007/978-3-642-84439-3_15 fatcat:mzsfh6besbg2bafsvlxmk2jqj4