The COMPTEL instrument on GRO is designed to image celestial gamma radiation in the approximately 0.7-30 MeV region of nuclear lines. Within a large field of view of about 1 sr its angular resolution of about 1 deg enables mapping of extended emission and location of (strong) point sources to an accuracy of better than 0.5 deg. The Galactic center region was observed by COMPTEL for a 2-week period in July 1991. Here we report the detection of the line at 1.8 MeV attributed to Al-26, addressing in particular the extent of the emission and the 1.8 MeV line flux.
Astronomy and Astrophysics Supplement Series
European Southern Observatory (ESO)
R. Diehl, K. Bennett, H. Bloemen, H. de Boer, M. Busetta, W. Collmar, A. Connors, J.W. den Herder, C. de Vries, W. Hermsen, J. Knödelseder, L. Kuiper, G.G. Lichti, J. Lockwood, J. Macri, M. McConnell, D. Morris, R. Much, J. Ryan, V. Schönfelder, G. Simpson, J.G. Stacy, H. Steinle, A.W. Strong, B.N. Swanenburg, M. Varendorff, P. von Ballmoos, W. Webber, and C. Winkler. First results from COMPTEL measurement of the Al-26 1.8 MeV gamma-ray line from the Galactic center region. 1993, Astron. Astrophys. Suppl., v. 97, no. 1, pp. 181-184.