Recent Progress in Gamma-Ray Bursts: The Long and Short of It

Dale Frail

The discovery of long-lived X-ray, optical and radio afterglows from of gamma-ray bursts ushered in a new era in our understanding of these mysterious events. I will begin my talk with a summary of the progress made in understanding the progenitors of long-duration, soft-spectrum gamma-ray bursts, and proceed to show how we have used this experience to recently make significant progress in our understanding of short-duration, hard-spectrum gamma-ray bursts (SHBs).

From observations of the physics and environments of these explosions it appears that progenitor models requiring young stellar populations, such as magnetars and collapsars, are ruled out. Coalescing degenerate binaries remain the most promising progenitor candidate for SHBs.