High-resolution observations of gamma-ray line emission from SN 1987A

Abstract

Observations of SN 1987A made with a balloon-borne gamma-ray spectrometer comprising an array of high-purity germanium detectors on October 29-31, 1987 are presented. High resolution data, typically 2.5 keV at 1.33 MeV, were obtained for two transists of the supernova with interspersed background data. A preliminary estimation of line flux is presented. It is found that there is evidence of dynamical broadening of the 847 keV line. It is suggested that this line may be an emission from the first excited state of Fe-56 due to the radioactive decay of Co-56 providing evidence for nucleosynthesis in the supernova.