OSSE Observations of Blazars
Abstract
The Oriented Scintillation Spectrometer Experiment (OSSE) on the Compton Gamma Ray Observatory has observed four of the active galactic nuclei detected by EGRET (Fichtel et at. 1993) at photon energies above 100 MeV; namely, 3C 273, 3C 279, MRK 421 and PKS 0528+134. These sources show blazar properties at other wavelengths. Only 3C 273 and 3C 279 were detected with high significance in the OSSE energy range, 0.05 - 10 MeV. However, not all of the OSSE observations were contemporaneous with the EGRET detections. The OSSE exposures varied from 10 weeks on 3C 273 (in 8 separate viewing periods) to 3 weeks on PKS 0528+34. When combined with contemporaneous COMPTEL observations of these sources, we find strong evidence for spectral softening between the hard X-ray and medium energy gamma-ray bands in 3 of the 4 sources. Constraints provided by the OSSE observations on models of blazar emissions are discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1994
- Accession Number
- ADA464511
Entities
People
- D. A> Grabelsky
- G. V. Jung
- J. D. Kurfess
- J. E. Grove
- K. Mcnaron-brown
- R. A. Cameron
- R. A. Kroeger
- R. L. Kinzer
- W. N. Johnson
- W. R. Purcell
Organizations
- George Mason University