Live radioisotopes as signatures of nearby supernovae
Abstract
Nearby (≲1 kpc) supernovae were almost certainly common in earth's geological history. Such events allow the direct study of their freshly synthesized live radioisotopes, opening new windows onto supernovae. Very close supernovae (within a few tens of pc) may deposit radioisotopes directly on the earth. Recent high-sensitivity accelerator mass spectrometry measurements of deep-ocean samples find live 60Fe at levels that greatly exceed background, suggesting an explosion occurred within 30 pc during the last 5 Myr. Somewhat more distant - but also more frequent - supernovae leave observable signatures of radioisotopes whose decay includes γ-ray line emission. In particular, a large, old supernova remnant was recently discovered at ∼100 pc, and appears to contain 26Al. If confirmed, this would be the first detection of 26Al in a single remnant, and would be a new probe of supernova nucleosynthesis and astrophysics.
- Publication:
-
New Astronomy Reviews
- Pub Date:
- February 2004
- DOI:
- 10.1016/j.newar.2003.11.017
- Bibcode:
- 2004NewAR..48..119F
- Keywords:
-
- Supernovae;
- Nucleosynthesis;
- γ-rays;
- 26.30.+k;
- 98.70.Rz;
- 97.60.Bw;
- 92.20.Td;
- Nucleosynthesis in novae supernovae and other explosive environments;
- gamma-ray sources;
- gamma-ray bursts;
- Supernovae;
- Radioactivity and radioisotopes