Supernovae as the Site of ther‐Process: Implications for Gamma‐Ray Astronomy

We discuss how detection of gamma-ray emission from the decay of r-processnuclei can improve our understanding of r-process nucleosynthesis. We find thata gamma-ray detector with a sensitivity of 10**(-7)/cm**2/s at 100-700 keV maydetect the emission from the decay of Sb125, Cs137, Ce144, Eu155, and Os194produced in a future Galactic supernova. In addition, such a detector maydetect the emission from the decay of Sn126 in the Vela supernova remnant andthe diffuse emission from the decay of Sn126 produced by past supernovae in ourGalaxy. The required detector sensitivity is similar to what is projected forthe proposed Advanced Telescope for High Energy Nuclear Astrophysics (ATHENA).Both the detection of gamma-ray emission from the decay of several r-processnuclei (e.g., Sb125 and Os194) produced in future Galactic supernovae and thedetection of emission from the decay of Sn126 in the Vela supernova remnantwould prove that supernovae are a site of the r-process. Furthermore, theformer detection would allow us to determine whether or not the r-processnuclei are produced in relative proportions specified by the solar r-processabundance pattern in supernova r-process events. Finally, detection of diffuseemission from the decay of Sn126 in our Galaxy would eliminate neutronstar/neutron star mergers as the main source for the r-process nuclei near massnumber A=126.Comment: 14 pages, AASTeX, submitted to the Astrophysical Journa