Formula to calculate the ringdown frequency of two black holes given their mass?

Is there a simple formula to approximately calculate the ringdown frequency of two black holes given that we know their masses?

• You must at least need information about angular momentum given that ringdown is computed from perturbing a Kerr solution I believe. – tfb Mar 7 '17 at 0:54
• @tfb assuming I do have it, how would I calculate it? I am new to gravitational waves and don't know much other than a few trivial things. Is there a direct formula I would understand? – Rahul Aedula Mar 7 '17 at 13:12
• I assume that the answer is 'hairy numerical model running on a supercomputer'. In other words I assume there's no easy way to do this. I believe that numerical models which work for this sort of thing are fairly recent -- I have '2005' in my head but I'm not sure if that's right. The place to look would probably be LIGO papers, as they are the canonical people who need to do this. – tfb Mar 7 '17 at 15:36