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Title: Cosmic radioactivity and INTEGRAL results

Gamma-ray lines from radioactive decay of unstable isotopes co-produced by nucleosynthesis in massive stars and supernova have been measured since more than thirty years. Over the past ten years, INTEGRAL complemented the first sky survey made by COMPTEL. The {sup 26}A1 isotope with 1 My decay time had been first direct proof of currently-ongoing nucleosynthesis in our Galaxy. This has now become a tool to study the ∼My history of specific source regions, such as massive-star groups and associations in nearby regions which can be discriminated from the galactic-plane background, and the inner Galaxy, where Doppler shifted lines add to the astronomical information about bar and spiral structure. Recent findings suggest that superbubbles show a remarkable asymmetry, on average, in the spiral arms of our galaxy. {sup 60}Fe is co-produced by the sources of {sup 26}A1, and the isotopic ratio from their nucleosynthesis encodes stellar-structure information. Annihilation gamma-rays from positrons in interstellar space show a puzzling bright and extended source region central to our Galaxy, but also may be partly related to nucleosynthesis. {sup 56}Ni and {sup 44}Ti isotope gamma-rays have been used to constrain supernova explosion mechanisms. Here we report latest results using the accumulated multi-year database of INTEGRALmore » observations, and discuss their astrophysical interpretations, connecting to other traces of cosmic radioactivity and to other cosmic messengers.« less
Authors:
 [1]
  1. Max Planck Institut für Extraterrestrische Physik, D-85748 Garching, Germany and Excellence Cluster Origin and Evolution of the Universe', D-85748 Garching (Germany)
Publication Date:
OSTI Identifier:
22280447
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1594; Journal Issue: 1; Conference: OMEG12: 12. international symposium on origin of matter and evolution of galaxies, Tsukuba (Japan), 18-21 Nov 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANNIHILATION; ASTROPHYSICS; COSMIC POSITRONS; DOPPLER EFFECT; GALAXIES; GAMMA DECAY; GAMMA DETECTION; GAMMA RADIATION; GIANT STARS; INTERSTELLAR SPACE; IRON 60; ISOTOPE RATIO; NICKEL 56; NUCLEOSYNTHESIS; SUPERNOVAE; TITANIUM 44