Abstract
We report the first ever detection of 56 Co lines at 847 and 1237 keV and a continuum in the 200-400 keV band from the Type Ia supernova SN2014J in M82 with INTEGRAL observatory. The data were taken between 50th and 100th day since the SN2014J outburst. The line fluxes suggest that 0.62 ± 0.13 M of radioactive 56 Ni were synthesized during the explosion. Line broadening gives a characteristic ejecta expansion velocity Ve ∼ 2100 ± 500 km s −1. The flux at lower energies (200-400 keV) flux is consistent with the three-photon positronium annihilation, Compton downscattering and absorption in the ∼ 1.4 M ejecta composed from equal fractions of iron-group and intermediate-mass elements and a kinetic energy Ek ∼ 1.4 10 51 erg. All these parameters are in broad agreement with a " canonical " model of an explosion of a Chandrasekhar-mass White Dwarf (WD), providing an unambiguous proof of the nature of Type Ia supernovae as a thermonuclear explosion of a solar mass compact object.