0120148

SN1987 A in the Large Magellanic Cloud is a once-in-a-lifetime opportunity to observe gamma-ray emission from a Type II supernova with INTEGRAL. The radioactive isotope 44Ti emitter of gamma-ray photons at 67.9 78.4 and 1157 keV is an ideal tracer to probe core collapse physics since it is created in appreciable amounts in the innermost layers of the exploding star. Radioactive decay of 60Co accompanied by gamma-ray line emission at 1173 and 1332 keV is sensitive to the neutron excess in the supernova providing a unique chance for a direct measurement of this important parameter. Therefore we propose to search for the gamma-ray line signatures that arise from the decay of 44Ti and 60Co produced in SN1987 A. The measurement of the gamma-ray line fluxes will allow the determination of the 44Ti and 60Co yields in SN1987 A providing information about the position of the mass-cut the maximum temperature and density reached during the passage of the shock wave in the ejecta and the neutron excess. The 44Ti line profile will provide excellent information about the velocity structure of the ejecta close to the mass-cut and probes the pre-supernova composition inside 2 Msol. We will use both SPI and IBIS to search for the three gamma-ray lines of 44Ti although we only expect to detect the 1157 keV line with SPI within the requested 2000 kiloseconds of exposure time. 60Co is certainly an observational challenge but due to the rapid decay of this isotope INTEGRAL probably represents the last chance to measure its gamma-ray lines in SN1987 A. In addition to the 2000 kiloseconds we also request the data rights for all additional observations of the LMC region in order to search for the 44Ti and 60Co decay signatures of SN1987 A. [truncated! Please see actual data for full text]