Speaker
Description
We consider the question of whether core-collapse supernovae (CCSNe) can produce rapid neutron
capture process (r-process) elements and how future MeV gamma-ray observations could address this.
Rare types of CCSNe characterized by substantial magnetic fields and rotation, known as magnetorotational supernovae (MR-SNe), are theoretically predicted to produce these elements, although direct
observational evidence is lacking. We suggest that this critical question be addressed through the
study of some of the eleven CCSN remnants located within 10 kpc, as well as through the detection
of gamma-ray emission from a future Galactic supernova. We use a two-dimensional MR-SN model
to estimate the expected gamma flux stemming from nuclear decays in the range of a few tens of keV
to a few MeV. Our results indicate that an observation of 126Sn (126Sb) in a remnant stands out as
a signature of an r-process-producing supernova. Since the neutron-rich conditions that lead to the
production of the r-process could also enhance the production of 60Fe, the detection of substantial 60Fe
(
60Co) would be indicative of favorable conditions for the r-process. In the case of a future supernova
explosion, when the evolution of the spectrum is studied over ten days to a few years, a rich picture
emerges. At various epochs, second peak r-process isotopes such as 125Sn, 131I, 131Te, 132I and 140La
produce gamma-ray signals that emerge above the background from explosive burning products and
electron–positron annihilation. The weak r-process isotopes 95Nb, 103Ru, 106Rh also have periods of
prominence. While MR-SNe are predicted to have a relatively small main r-process contribution, third
peak isotopes like 194Ir could still be above next generation MeV gamma instrument sensitivities.
| Career stage | Graduate student |
|---|