Key Results from the Oriented Scintillation Spectrometer Experiment
NAVAL RESEARCH LAB WASHINGTON DC
Pagination or Media Count:
Key results obtained by the OSSE instrument during the first four years of the Compton Gamma Ray Observatory mission are presented. OSSE has undertaken extended observations of the gamma ray emission from the galactic center region and found the positron annihilation radiation to be consistent with a two-component model a spheroidal component located at the galactic center and a weaker galactic disk component. Simultaneous observations with the SIGMA imaging instrument have provided the first low-energy gamma ray spectrum of the diffuse continuum emission from the galactic center region. Results on galactic sources include the spectral observations of two new rotation-powered pulsars, PSR 1509-58 and Vela, the discovery of 110 keV cyclotron emission from the Be X-ray binary A053526, and the discovery that galactic black hole transients have two spectral classes thermal and power-law. Extragalactic sources also have two spectral classes. Seyfert galaxies are typified by thermal spectral with exponential cutoffs from 50-300 keV, and blazars which exhibit power-law spectra that extend into the EGRET energy range. Blazar spectra also often have a spectral break in the MeV region.
- Atomic and Molecular Physics and Spectroscopy