Resonant Excitation of Disk Oscillations in Deformed Disks V: Effects of Dissipative Process

Abstract

It is suggested that a set of positive- and negative-energy oscillations can be resonantly excited in the inner region of deformed (warped or eccentric) relativistic disks. In this paper we examine how a dissipative process affects on this wave excitation process. The results show that when the resonant condition in frequency is roughly satisfied and thus the oscillations are excited, introduction of a dissipative process works so as to decrease the growth rate of the oscillations. When the frequency difference of the two oscillations deviates more than a certain amount from that required by resonant condition, however, the oscillations are excited by introduction of dissipative process. This excitation by dissipative process can be understood as a special example of the double-diffusive instability.Comment: 14 pages, 2 figures, to be published in PASJ 63, No 2 (2011