The g-mode Excitation in the Proto Neutron Star by the Standing Accretion Shock Instability

The so-called ”acoustic revival mechanism” of core-collapse supernova proposed recently by the Arizona group is an interesting new possibility. Aiming to understand the elementary processes involved in the mechanism, we have calculated the eigen frequencies and eigen functions for the g-mode oscillations of a non-rotating proto neutron star. The g-modes have relatively small eigen frequencies. Since there is a convective region inside the proto neutron star, the eigen functions are confined either to the exterior or interior of this evanescent region although some fraction of eigen functions penetrates it because of their long wave lengths. The possible excitation of these modes by the standing accretion shock instability, or SASI, is discussed based on these eigen functions. Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan