Gamma-Ray lines from the galaxy: the GRO revolution
Abstract
The Compton Gamma-Ray Observatory (GRO) functioned flawlessly for more than 8 years. Its accomplishments, both in novelty and breadth, have virtually revolutionized the field of gamma-ray astrophysics. Since the review of its entire palette of results would be outside the scope of the present review, we will limit ourselves to the sub-field of Galactic gamma-ray lines; furthermore, we will have to neglect the minor topic of very-high energy gamma-ray lines (pion decay, axion annihilation, etc.). This review is divided into three main parts, plus an introduction presenting GRO and a summary in the form of a table showing the original objectives, GRO's accomplishments, and the remaining goals in each sub-field. The first main part deals with the knowledge gained from long and extensive observations of the Galactic electron-positron annihilation line radiation; the second major section treats the Galactic lines from radioactive isotope decay; the third major section discusses advances (and recent failures) in the very interesting field of Galactic nuclear de-excitation lines. In each case, an effort will be made not only to present the current knowledge in the field, but to particularly highlight the contribution made by GRO to our knowledge.
- Publication:
-
Astrophysics and Space Science
- Pub Date:
- September 2000
- Bibcode:
- 2000Ap&SS.273..171G