SIMBAD references

The COMPTEL telescope aboard the Compton Gamma-Ray Observatory (CGRO) is capable of imaging gamma-ray line sources in the MeV region with a sensitivity of the order 10^–5 photons/(cm².s). During two observation periods in July 1992 and February 1993 the Galactic plane in the region of the young supernova remnant Cas A was observed, showing evidence for line emission at 1.16 MeV from the decay of ⁴⁴Ti at a significance level of ∼4 sigma. This is the first time a supernova remnant has been detected in the gamma-ray line from ⁴⁴Ti decay. Adopting a distance of 2.8 kpc to the Cas A remnant, the measured line flux (7.0±1.7).10^–5 photons/(cm².s), can be translated into a ⁴⁴Ti mass ejected during the Cas A supernova explosion, between (1.4±0.4).10^–4 M_sun and (3.2±0.8).10^–4 M_sun, depending on the precise value of the ⁴⁴Ti mean life time and on the precise date of the event. Implications of this result for supernova nucleosynthesis models are discussed.