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Millimetre Continuum Variations, VLBI Structure and Gamma-rays: Investigating Shocked Jet Physics

Published online by Cambridge University Press:  05 March 2013

E. Valtaoja ,
T. Savolainen ,
K. Wiik  and
A. Lähteenmäki
E. Valtaoja*
Affiliation:
Tuorla Observatory, FIN-21500 Piikkiö, Finland Department of Physics, Turku University, FIN-20100 Turku, Finland
T. Savolainen
Affiliation:
Tuorla Observatory, FIN-21500 Piikkiö, Finland
K. Wiik
Affiliation:
Tuorla Observatory, FIN-21500 Piikkiö, Finland Metsähovi Radio Observatory, Helsinki University of Technology, FIN-02540 Kylmälä, Finland
A. Lähteenmäki
Affiliation:
Metsähovi Radio Observatory, Helsinki University of Technology, FIN-02540 Kylmälä, Finland
*
esko.valtaoja@utu.fi
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Abstract

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We compare the total flux density variations and the VLBI structural variations in a sample of 27 gamma-ray blazars. We find that all the radio variations are due to shocks; the flux of the underlying jet remains constant. A large fraction of the shocks grow and fade within the innermost 0.1 mas, appearing only as ‘core flares’. Comparisons with the EGRET data show that gamma-ray flares must come from the shocks, not from the jet. At the time of an EGRET flare, the shock is typically already over a parsec downstream from the radio core, beyond the accretion disk and/or the broad line region (BLR) photon fields. Thus, present models for gamma-ray production are inadequate, since they typically model the gamma-ray inverse Compton flux as coming from the jet, with significant disk or BLR external Compton components.

Keywords

galaxies: activegalaxies: jetsquasars: generalradio continuum: galaxiestechniques: interferometric
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 19 , Issue 1 , 2002 , pp. 117 - 121
Copyright
Copyright © Astronomical Society of Australia 2002

References

Abraham, Z., Carrara, E. A., Zensus, J. A., & Unwin, S. C. 1996, A&AS, 115, 543 Google Scholar
Böttcher, M., & Bloom, S. D. 2000, AJ, 119, 469 Google Scholar
Britzen, S., Witzel, A., Krichbaum, T. P., Campbell, R. M., Wagner, S. J., & Qian, S. J. 2000, A&A, 360, 65 Google Scholar
Ghisellini, G., Celotti, A., Fossati, G., Maraschi, L., & Comastri, A. 1998, MNRAS, 301, 451 CrossRefGoogle Scholar
Hartman, R. C., et al. 2001, ApJ, 553, 683 CrossRefGoogle Scholar
Hughes, P. A., Aller, H. D., & Aller, M. F. 1985, ApJ, 298, 301 Google Scholar
Jorstad, S. G., Marscher, A. P., Mattox, J. R., Wehrle, A. E., Bloom, S. D., & Yurchenko, A. V. 2001a, ApJS, 134, 181 Google Scholar
Jorstad, S. G., Marscher, A. P., Mattox, J. R., Aller, M. F., Aller, H. D., Wehrle, A. E., & Bloom, S. D. 2001b, ApJ, 556, 738 Google Scholar
Krichbaum, T. P., Krauss, A., Otterbein, K., Britzen, S., Witzel, A., & Zensus, J. A. 1998, in Radio Emission from Galactic and Extragalactic Compact Sources, IAU Colloquium 164, eds J. A. Zensus, G. B. Taylor, & J. B. Wrobel (San Francisco: ASP), 37 Google Scholar
Lähteenmäki, A., & Valtaoja, E. 1999, ApJ, 521, 493 CrossRefGoogle Scholar
Marscher, A. P., & Gear, W. K. 1985, ApJ, 298, 114 Google Scholar
Stevens, J. A., Litchfield, S. J., Robson, E. I., Hughes, D. H., Gear, W. K., Teräsranta, H., Valtaoja, E., & Tornikoski, M. 1994, ApJ, 437, 91 Google Scholar
Teräsranta, H., et al. 1998, A&AS, 132, 305 Google Scholar
Türler, M., Courvoisier, T. J.-L., & Paltani, S. 1999, A&A, 349, 45 Google Scholar
Valtaoja, E., & Teräsranta, H. 1995, A&A, 297, L13 Google Scholar
Valtaoja, E., & Teräsranta, H. 1996, A&AS, 120, 491 Google Scholar
Valtaoja, E., Lähteenmäki, A., Teräsranta, H., & Lainela, M. 1999, ApJS, 120, 95 Google Scholar
Valtaoja, E., Teräsranta, H., Urpo, S., Nesterov, N. S., Lainela, M., & Valtonen, M. 1992, A&A, 254, 71 Google Scholar
Valtaoja, E., et al. 1988, A&A, 203, 1 Google Scholar
Wehrle, A. E., Piner, B. G., Unwin, S. C., Zook, A. C., Xu, W., Marscher, A. P., Teräsranta, H., & Valtaoja, E. 2001, ApJS, 133, 297 Google Scholar