Gravitational Radiation from a Particle Falling Radially into a Schwarzschild Black Hole

We have computed the spectrum and energy of gravitational radiation from a "point test particle" of mass m falling radially into a Schwarzschild black hole of mass Mm. The total energy radiated is about 0.0104mc²(m/M), 4 to 6 times larger than previous estimates; the energy is distributed among multipoles according to the empirical law E_2l-pole≈(0.44m²c²M)e^-2l; and the total spectrum peaks at an angular frequency ω=0.32c³GM.