COMPTEL observations of the gamma-ray blazar PKS 1622-297
We report results of observations and analyses on the -ray blazar PKS 1622-297, with emphasis on the COMPTEL data (0.75-30 MeV) collected between April 1991 and November 1997. PKS 1622-297 was detected as a source of -rays by the EGRET experiment aboard CGRO in 1995 during a -ray outburst at energies above 100 MeV lasting for five weeks. In this time period the blazar was significantly (~5.9 ) detected by COMPTEL at 10-30 MeV. At lower COMPTEL energies the detection is marginal, resulting in a hard MeV spectrum. The combined COMPTEL/EGRET energy spectrum shows a break at MeV energies. The broad-band spectrum (radio - -rays) shows that the -ray emission dominates the overall power output. On top of the 5-week -ray outburst, EGRET detected a huge flare lasting for >1 day. Enhanced MeV emission (10-30 MeV) is found near the time of this flare, suggesting a possible time delay with respect to the emission above 100 MeV. Outside the 5-week flaring period in 1995, we do not detect MeV emission from PKS 1622-297.
Astronomy and Astrophysics
Digital Object Identifier (DOI)
COMPTEL observations of the gamma-ray blazar PKS 1622-297 S. Zhang, W. Collmar, K. Bennett, H. Bloemen, W. Hermsen, M. McConnell, O. Reimer, V. Schönfelder, S. J. Wagner, O. R. Williams A&A 386 (3) 843-853 (2002) DOI: 10.1051/0004-6361:20020267
© ESO 2002