Shading and Smothering of Gamma-Ray Bursts

The gamma ray burst (GRB) 980425 is distinctive in that it seems to beassociated with supernova (SN) 1998bw, has no X-ray afterglow, and has a singlepeak light curve and a soft spectrum. The supernova is itself unusual in thatits expansion velocity exceeds c/6. We suggest that many of these features canbe accounted for with the hypothesis that we observe the GRB along a penumbralline of sight that contains mainly photons that have scattered off ejectedbaryons. The hypothesis suggests a baryon poor jet (BPJ) existing within abaryon rich outflow. The sharp distinction can be attributed to whether or notthe magnetic field lines thread an event horizon. Such a configuration suggeststhat there will be some non-thermal acceleration of pick-up ex-neutrons withinthe BPJ. This scenario might produce observable spallation products andneutrinos.Comment: 7 pages, 2 figures, submitted to ApJ