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On The Location of the Acceleration and Emission Sites in Gamma-Ray Blazars

Published online by Cambridge University Press:  12 April 2016

Charles D. Dermer
Affiliation:
E. O. Hulburt Center for Space Physics, Code 7653, Naval Research Laboratory, Washington, DC 20375-5352
Reinhard Schlickeiser
Affiliation:
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn 1, Germany

Abstract

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Compton scattering of external radiation by nonthermal particles in outflowing blazar jets is dominated by accretion-disk photons rather than scattered radiation to distances ~ 0.01-0.1 pc from the central engine for standard parameters, thus clarifying the limits of validity of the model by the present authors and the model of Sikora, Begelman, & Rees. On the basis of contemporaneous Ginga X-ray and EGRET gamma-ray observations, we estimate the radius of 3C 279’s gamma-ray photosphere to be smaller than estimated by Blandford. There is thus no need to require that the acceleration and emission sites of gamma-ray blazars to be located farther than ~ 102 - 103 gravitational radii from the central engine. We argue that lineless BL Lac objects, rather than quasars, are more likely to be detected in the TeV energy range.

Subject headings: acceleration of particles — BL Lacertae objects: general — galaxies: jets — gamma rays: theory — radiation mechanisms: nonthermal

Type
Active Galaxies and Quasi-Stellar Objects
Copyright
Copyright © The American Astronomical Society 1994

References

Blandford, R.D. 1992, in Proc. Compton Gamma-Ray Observatory Symp., ed. Friedlander, M., Gehrels, N., & Macomb, D.J. (New York: AIP), 533 Google Scholar
Brown, R.W., Mikaelian, K.O., & Gould, R.J. 1973, Astrophys. Letters, 14, 203 Google Scholar
Dermer, C.D., & Schlickeiser, R. 1992, Science, 257, 1642 Google Scholar
Dermer, C.D., & Schlickeiser, R. 1993, ApJ, 416, 458 (DS)CrossRefGoogle Scholar
Dermer, C.D., Schlickeiser, R., & Mastichiadis, A. 1992, A&A, 256, L27 Google Scholar
Fennell, S., et al. 1993, in Proc. Compton Gamma-Ray Observatory Symp., ed. Friedlander, M., Gehrels, N., & Macomb, D.J. (New York: AIP), 508 Google Scholar
Fichtel, C.E., et al. 1993, in Proc. Compton Gamma-Ray Observatory Symp., ed. Friedlander, M., Gehrels, N., & Macomb, D.J. (New York: AIP), 461 Google Scholar
Gould, R.J., & Schréder, G.P. 1967, Phys. Rev., 155, 1404 Google Scholar
Kniffen, D.A., et al. 1993, ApJ, 411, 133 CrossRefGoogle Scholar
Lawrence, A. 1987, PASP, 99, 309 Google Scholar
Makino, F. 1993, private communicationGoogle Scholar
Makino, F., et al. 1989, ApJ, 347, L9 Google Scholar
Makino, F., et al. 1993, in Internat. Symp. on Neutrino Astrophysics, Takayam/ Kamioka, Japan (1992 October 19-22) in pressGoogle Scholar
Punch, M., et al. 1992, Nature, 358, 477 CrossRefGoogle Scholar
Rybicki, G.B., & Lightman, A.P. 1979, Radiative Processes in Astrophysics (John Wiley) (New York: Wiley)Google Scholar
Sikora, M., Begelman, M.C., & Rees, M.J. 1993, in Proc. Compton Gamma-Ray Observatory Symp., ed. Friedlander, M., Gehrels, N., & Macomb, D.J. (New York: AIP), 598 Google Scholar
Sikora, M., Begelman, M.C., & Rees, M.J. 1994, ApJ, in pressGoogle Scholar
Stecker, F.W., de Jager, O.C., & Salamon, M.H. 1992, ApJ, 390, L49 CrossRefGoogle Scholar
Turner, M.J.L., et al. 1989, in Proc. 23d ESLAB Symp. Two Topics in X-Ray Astronomy, Vol. 2, ed. White, N.E. (Noordwijk: ESA), 769 Google Scholar
Zdziarski, A.A., & Lightman, A.P. 1985, ApJ, 294, L79 Google Scholar