Context : The detection and measurement of gamma-ray lines from the decay chain of ^ { 56 } Ni provides unique information about the explosion in supernovae .
SN2014J at 3.3 Mpc is a sufficiently nearby supernova of type Ia so that such measurements have been feasible with the gamma-ray spectrometer SPI on ESA ’ s INTEGRAL gamma-ray observatory .

Aims : The ^ { 56 } Ni freshly-produced in the supernova is understood to power the optical light curve , as it emits gamma-rays upon its radioactive decay first to ^ { 56 } Co and then to ^ { 56 } Fe .
Gamma-ray lines from ^ { 56 } Co decay are expected to become directly visible through the overlying white dwarf material several weeks after the explosion , as they progressively penetrate the overlying material of the supernova envelope , diluted as it expands .
The lines are expected to be Doppler-shifted or broadened from the kinematics of the ^ { 56 } Ni ejecta .
We aim to exploit high-resolution gamma-ray spectroscopy with the SPI spectrometer on INTEGRAL towards constraining the ^ { 56 } Ni distribution and kinematics in this supernova .

Methods : We use the observations with the SPI spectrometer on INTEGRAL together with an improved instrumental background method .

Results : We detect the two main lines from ^ { 56 } Co decay at 847 and 1238 keV , significantly Doppler-broadened , and at intensities ( 3.65 \pm 1.21 ) 10 ^ { -4 } and ( 2.27 \pm 0.69 ) 10 ^ { -4 } ph cm ^ { -2 } s ^ { -1 } , respectively , at brightness maximum .
We measure their rise towards a maximum after about 60–100 days and decline thereafter .
The intensity ratio of the two lines is found consistent with expectations from ^ { 56 } Co decay ( 0.62 \pm 0.28 at brightness maximum , expected is 0.68 ) .
We find that the broad lines seen in the late , gamma-ray transparent phase are not representative for the early gamma-ray emission , and rather notice the emission spectrum to be complex and irregular until the supernova is fully transparent to gamma-rays , with progressive uncovering of the bulk of ^ { 56 } Ni .
We infer that the explosion morphology is not spherically symmetric , both in the distribution of ^ { 56 } Ni and of the unburnt material which occults the ^ { 56 } Co emission .
Comparing light curves from different plausible models , the resulting ^ { 56 } Ni mass is determined as 0.49 \pm 0.09 M _ { \odot } .

Conclusions :