# Question regarding maximum accretion of black holes

1. Apr 26, 2013

### can't.do.phys

So I've got a question that I can't seem to figure out.

If the accretion efficiency of a black hole is L=εM(dot)c2 with ε=0.1
I have to set this to the Eddington luminosity which is Ledd = 4πcGMmpT to find the maximum rate at which a black hole can accrete by. I found that κ=mpT so I substituted that but then I got stuck. Has it got something to do with the accretion disk being optically thin? the answer should be M(dot)=κM but i can't figure out how to get it. help?

2. Apr 27, 2013

### Chronos

Try not assuming there is a maximum accretion rate.