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COMPTEL Observations of the Blazar PKS 1622-297 during a Gamma-Ray High State in 1995

S. Zhang·W. Collmar·V. Schonfelder·H. Bloemen·W. Hermsen·J. Ryan·K. Bennett·O. R. Williams·O. Reimer
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Abstract

PKS 1622-297 was detected as a source of gamma-rays by the EGRET experiment at energies above 100 MeV during a gamma-ray outburst June and July 1995. We analyzed the COMPTEL data (0.75 - 30 MeV) of this time period to investigate the behaviour of PKS 1622-297 at lower gamma-ray energies. The blazar is significantly (5.7 sigma) detected by COMPTEL at energies above 10 MeV. Below 10 MeV the source is only marginally (3-10 MeV band) or not (below 3 MeV) detected. The summed MeV spectrum shows a 'hard' (alpha < 2, ~ E^(-alpha)) shape and, if combined with the simultaneous EGRET spectrum, a spectral break at MeV energies is indicated. We present the COMPTEL results (light curves, spectra) and compare them to results derived in neighbouring energy bands, in particular to the EGRET one.

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S. Zhang, W. Collmar, V. Schonfelder, H. Bloemen, W. Hermsen, J. Ryan, K. Bennett, O. R. Williams, O. Reimer. 2001-05-11. COMPTEL Observations of the Blazar PKS 1622-297 during a Gamma-Ray High State in 1995. https://arxiv.org/abs/astro-ph/0105191

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