How Did Supermassive Black Holes Grow So Massive So Quickly?

[wolram]

What is the origin of the M-sigma relation between supermassive black hole mass and galaxy velocity dispersion?] How did the most distant quasars grow their supermassive black holes up to 109 solar masses so early in the history of the Universe?

 

[Chalnoth]

What is the origin of the M-sigma relation between supermassive black hole mass and galaxy velocity dispersion?] How did the most distant quasars grow their supermassive black holes up to 109 solar masses so early in the history of the Universe?

This is an area of active research and is as yet unknown. The physics of black holes and the matter around them are horrifically complex.

Here's one fairly recent article that talks about one of the mechanisms that is relevant:
http://sci.esa.int/herschel/50333-powerful-black-holes-quenched-galaxy-star-formation/

 

[wolram]

Astronomers had long suspected that black holes could exert such negative feedback on their host galaxy: the accretion process of matter onto a black hole is not completely efficient and can thus drive large amounts of the galaxy's interstellar matter outwards. These black-hole triggered winds would then deprive galaxies of the raw material needed to form stars. In recent years, evidence has mounted in support of this scenario; among others, a survey of galaxies performed with Herschel has shown, in 2011, that galactic outflows are indeed able to influence the entire galaxy's star formation.

What are these (winds) how are they produced?

 

[Chalnoth]

Astronomers had long suspected that black holes could exert such negative feedback on their host galaxy: the accretion process of matter onto a black hole is not completely efficient and can thus drive large amounts of the galaxy's interstellar matter outwards. These black-hole triggered winds would then deprive galaxies of the raw material needed to form stars. In recent years, evidence has mounted in support of this scenario; among others, a survey of galaxies performed with Herschel has shown, in 2011, that galactic outflows are indeed able to influence the entire galaxy's star formation.

What are these (winds) how are they produced?

I believe it's primarily radiation pressure from the active galactic nucleus acting on the galaxy's gas and dust.

 

[Torbjorn_L]

Here is a description how they could have grown from 10 to 10^10 solar masses in a billion years:

http://www.universetoday.com/113826/how-did-supermassive-black-holes-grow-so-massive-so-quickly/