Abstract:
Astronomical gamma-ray (?) lines with energy 0.5 - 15 MeV have been interpreted as due to e+ - e- annihilation and decay and de-excitation of the excited nucleosynthesis yields produced in some explosive sites and then ejected into the inter steller matter (ISM). Some explosive events e.g. X-ray outbursts and novae outbursts have been considered to study, whether these possible cosmic candidates can provide enough nuclei to explain the observed highly significant 1.809 MeV, 1.275 MeV ?-lines reported by Compton Gamma-Ray Observatory (CGRO) and other satellite experiments. Cen X-4, Aq1 X-1, 1608-522, these three soft X-ray transients (SXT) during outburst can be suggested as good emitters of these two lines with emission features in observable range which may be tried with sophisticated instruments like SPI (Spectrometer INTEGRAL) on board the spacecraft INTEGRAL (International Gamma-Ray Astrophysics Laboratory) to be launched by ESA (European Space Agency) in near future.