Gamma-Ray Line Astronomy
arXiv:astro-ph/0409674 · doi:10.1016/j.nuclphysa.2005.05.175
Abstract
Gamma-ray lines from radioactive isotopes, ejected into interstellar space by cosmic nucleosynthesis events, are observed with new space telescopes. The Compton Observatory had provided a sky survey for the isotopes 56Co, 22Na, 44Ti, and 26Al, detecting supernova radioactivity and the diffuse glow of long-lived radioactivity from massive stars in the Galaxy. High-resolution spectroscopy is now being exploited with Ge detectors: Since 2002, with ESA's INTEGRAL satellite and the RHESSI solar imager two space-based Ge-gamma-ray telescopes are in operation, measuring Doppler broadenings and line shape details of cosmic gamma-ray lines. First year's results include a detection and line shape measurement of annihilation emission, and 26Al emission from the inner Galaxy and from the Cygnus region. 60Fe gamma-ray intensity is surprisingly low; it may have been detected by RHESSI at 10% of the 26Al brightness, yet is not seen by INTEGRAL. 44Ti emission from Cas A and SN1987A is being studied; no other candidate young supernova remnants have been found through 44Ti. 22Na from novae still is not seen.
9 pages, 5 figures; invited review at "Nuclei in the Cosmos 8", Vancouver, CA; accepted for publication in Nucl Phys A
References in corpus (8)
- MeV Dark Matter: Has It Been Detected?
- Early SPI/INTEGRAL measurements of galactic 511 keV line emission from positron annihilation
- Early SPI/INTEGRAL contraints on the morphology of the 511 keV line emission in the 4th galactic quadrant
- SPI/INTEGRAL in-flight performance
- Radioactive Al26 and Fe60 in the Milky Way: implications of the RHESSI detection of Fe60
- The Reuven Ramaty High Energy Solar Spectroscopic Imager observation of the 1809 keV line from Galactic 26Al
- SPI Measurements of Galactic 26Al
- Line shape diagnostics of Galactic 26Al