On the enhanced X-ray emission from SGR 1900+14 after the August 27 giant flare

Abstract

We show that the giant flares of soft gamma-ray repeaters (E similar to 10(44) ergs) can push the inner regions of a fall- back disk out to larger radii by radiation pressure, while matter remains bound to the system for plausible parameters. The subsequent relaxation of this pushed-back matter can account for the observed enhanced X-ray emission after the August 27 giant flare of SGR 1900+14. Based on the results of our models, we estimate that the ratio of the fluences of the enhanced X-ray emissions to that of the preceding bursts remains constant for a particular SGR with similar preburst inner-disk conditions, which is consistent with the four different burst observations of SGR 1900+14.