Radionuclides with half-lives ranging from some years to billions of years presumably synthesized outside of the solar system are now recorded in "live" or "fossil" form in various types of materials, like meteorites or the galactic cosmic rays. They bring specific astrophysical messages concerning the nucleosynthetic sources of the radioactive species, as well as possibly the chronology of these production events, and the prehistory or early history of the solar system. Extant short-lived radionuclides are also present in to-day's interstellar medium, as testified by the gamma-ray lines emitted following the de-excitation of their daughter products. The deciphering of the various messages brought by the cosmic radioactivities is briefly reviewed, along with some recent developments in the field.
19th Texas Symposium on Relativistic Astrophysics and Cosmology
- Pub Date:
- December 1998