$^{60}$Fe in core-collapse supernovae and prospects for X-ray and $\gamma$-ray detection in supernova remnants
S. Jones, H. Moller, C. L. Fryer, C. J. Fontes, R. Trappitsch, W. P. Even, A. J. Couture, M. Mumpower, S. Safi-Harb
Published MNRAS stz536 2019 (2019)
We investigate \fe~in massive stars and core-collapse supernovae focusing on uncertainties that may influence the production of this radioactive nuclide. We find that the \fe~yield is a monotonic increasing function of the uncertain \feng~cross section and that a factor of 10 reduction in the reaction rate results in a factor $8-10$ reduction in the \fe~yield; while a factor of 10 increase in the rate increases the yield by a factor $4-7$. We find that none of the 189 simulations we have performed are consistent with a core-collapse supernova triggering the formation of the Solar System, and that only models using \feng~cross section that is less than or equal to that from NON-SMOKER can reproduce the observed \fe/\al~line flux ratio in the diffuse ISM. We examine the prospects of detecting old core-collapse supernova remnants (SNRs) in the Milky Way from their $\gamma$-ray emission from the decay of \fe, finding that the next generation of gamma-ray missions could be able to discover up to $\sim100$ such old SNRs as well as measure the \fe~yields of a handful of known Galactic SNRs. We also predict the X-ray spectrum that is produced by atomic transitions in \co~following its ionization by internal conversion and give theoretical X-ray line fluxes as a function of remnant age as well as the Doppler and fine-structure line broadening effects. The X-ray emission presents an interesting prospect for addressing the missing SNR problem with future X-ray missions.
LA-UR-18-24048