A&A 436, 763-784 (2005)
Resonant absorption troughs in the gamma-ray spectra of QSOA. F. Iyudin1, O. Reimer2, V. Burwitz1, J. Greiner1 and A. Reimer2
1 Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany
2 Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, 44780 Bochum, Germany
(Received 9 August 2004 / Accepted 11 February 2005 )
We report the very first evidence of the possible detection of -ray resonant absorption along the line of sight towards -ray bright quasars (QSOs), like 3C 279, 3C 273, PKS 0528+0134, and BL Lacertae. These detections resulted from the analysis of COMPTEL and EGRET data that were collected either during monitoring campaigns of the Virgo and galactic anticenter regions by the Compton Gamma Ray Observatory (CGRO) or during ToO observations of QSOs flares.
Key words: galaxies: active -- galaxies: quasars: absorption lines -- gamma-rays: observations -- ISM: general
© ESO 2005