COMPTEL observations of the gamma-ray blazar PKS 1622-297

Academic Article

Abstract

  • We report results of observations and analyses on the gamma-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 gamma-rays by the EGRET experiment aboard CGRO in 1995 during a gamma-ray outburst at energies above 100 MeV lasting for five weeks. In this time period the blazar was significantly (~ 5.9 sigma) 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 - gamma-rays) shows that the gamma-ray emission dominates the overall power output. On top of the 5-week gamma-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.
  • Authors

  • Zhang, S
  • Collmar, W
  • Bennett, K
  • Bloemen, H
  • Hermsen, W
  • McConnell, Mark
  • Reimer, O
  • Schonfelder, V
  • Wagner, SJ
  • Williams, OR
  • Status

    Publication Date

  • May 2002
  • Has Subject Area

    Keywords

  • galaxies : active
  • galaxies : quasars : individual : PKS 1622-297
  • gamma rays : observations
  • Digital Object Identifier (doi)

    Start Page

  • 843
  • End Page

  • 853
  • Volume

  • 386
  • Issue

  • 3