1998/12/06 by David Eichler, D. Eichler, Amir Levinson +1 · 3 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Galaxy #Gamma-ray burst #Gamma-ray bursts and supernovae #Light curve #Line (geometry) #Line-of-sight #Neutrino Physics Research #Observable #Photon #Smothering #Supernova #astro-ph
paper · pdf · doi:10.1086/312187
7 pages, 2 figures, submitted to ApJL
arxiv created 1998/12/06 · openalex publication_date 1999/08/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
GRB 980425 is distinctive in that it seems to be associated with SN 1998bw, has no X-ray afterglow, and has a rounded, structureless, single-peak light curve and a relatively soft spectrum. The supernova is itself unusual in that its expansion velocity exceeds c /6. We suggest that many of these features can be accounted for with the hypothesis that we observe the gamma-ray burst along a penumbral line of sight that contains mainly photons that have scattered off ejected baryons. The hypothesis suggests a baryon-poor jet existing within a baryon-rich outflow. The sharp distinction can be attributed to whether or not the magnetic field lines thread an event horizon. Such a configuration suggests that there will be some nonthermal acceleration of pickup ex-neutrons within the baryon-poor jet. This scenario might produce observable spallation products and neutrinos.