Abstract

Contributed Talk - Splinter SNR

Thursday, 12 September 2024, 14:45   (S14)

Production of unstable isotopes iron-60 in the supernova clusters

Xin-Yue Shi [1,2], Martin Pohl [1,3], Michael Schulreich [4]
[1] Deutsches Elektronen-Synchrotron DESY, Zeuthen, Germany; [2] School of Astronomy and Space Science, Nanjing University, Nanjing, China; [3] Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany; [4] Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Berlin, Germany

The supernovae remnants are known as promising sites for accelerating particles to relativistic energies, offering persistent targets to study cosmic-ray acceleration across various wavebands. The unstable isotope of iron-60(^{60}Fe) with a half-life of million years, is produced only in supernova explosions. The observed presence of ^{60}Fe in cosmic rays and its detection in deep-sea crusts and sediments suggest its acceleration from the supernova ejecta or the enrichment of the circumstellar material around the supernova progenitors, indicating cosmic ray production in clusters of supernovae. In our study, we focus on the latter scenario, using the time-dependent acceleration code RATPaC to investigate the spectrum of various isotopes, including protons, and ^{60}Fe, within the ambient environment of several supernovae-generated local bubbles right before the last supernova explosion. The transport equations for cosmic rays in test-particle approximation and for the magnetic field have been solved simultaneously with the hydrodynamic equations in 1-D spherical symmetry. The evolution of iron-60 mass ratio within the local bubble is also tracked simultaneously and independently using passive scalars. We calculate and compare the momentum spectra of the proton and ^{60}Fe, interpreting their observed features among cosmic rays under different magnetic field assumptions. The insights gained from this study contribute to a deeper understanding of cosmic ray origins and the role of supernovae in their production.