Quasinormal modes of Schwarzschild black holes: The determination of quasinormal frequencies with very large imaginary parts

We present an improvement of the continued fraction technique for the numerical calculation of quasinormal modes of Schwarzschild black holes. On this basis it becomes possible to compute quasinormal frequencies with arbitrary imaginary parts. We use this technique for a very accurate numerical determination of the asymptotic behavior of quasinormal frequencies with very large imaginary parts Im () 100.