Yet Another Model of Soft Gamma Repeaters

Abstract

We develop a model of SGR in which a supernova leaves planets orbiting a neutron star in intersecting eccentric orbits. These planets will collide in $\sim 10^4$ years if their orbits are coplanar. Some fragments of debris lose their angular momentum in the collision and fall onto the neutron star, producing a SGR. The initial accretion of matter left by the collision with essentially no angular momentum may produce a superburst like that of March 5, 1979, while debris fragments which later lose their angular momentum produce an irregular pattern of smaller bursts.