Imprints of accretion on gravitational waves from black holes - art. no. 044016

We explore the subtleties that may emerge if mass accretion events increase significantly the mass of a black hole horizon during its: gravitational w ave (GW) emission. We find that horizon growth extends the phenomenology of black hole ring-down in a well defined manner. The resulting GW signals ar e best described as amplitude and frequency (AM-FM) modulated versions of t he simple damped sinusoidal wave forms. Any appreciable increase in the hor izon mass during emission reflects on the instantaneous signal frequency, w hich shows a prominent negative branch in the f(f) evolution diagram. The f eatures of the frequency evolution pattern reveal key properties of the acc retion event, such as the rural accreted mass and the accretion rate. For s low accretion rates the frequency evolution follows verbatim the accretion rate, as expected from dimensional arguments.