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Time-variable linear polarization as a probe of the physical conditions in the compact jets of blazars

Published online by Cambridge University Press:  24 March 2015

Alan P. Marscher
Alan P. Marscher*
Affiliation:
Institute for Astrophysical Research, Boston University 725 Commonwealth Ave., Boston, MA 02215, USA email: [email protected]
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Abstract

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A single measurement of linear polarization of a nonthermal source provides direct information about the mean direction and level of ordering of the magnetic field. Monitoring of the polarization in blazars, combined with millimeter-wave VLBI imaging in both total and polarized intensity, has the potential to determine the geometry of the magnetic field. This is a key probe of the physical processes in the relativistic jet, such as ordered field components, turbulence, magnetic reconnections, magnetic collimation and acceleration of the jet flow, particle acceleration, and radiative processes that produce extremely luminous, highly variable nonthermal emission. Well-sampled monitoring observations of multi-waveband flux and radio-optical polarization of blazars show a variety of behavior. In some cases, the observed polarization patterns appear systematic, while in others randomness dominates. Explanations involve helical magnetic fields, turbulence, and perhaps particle acceleration that depends on the angle between the magnetic field and shock fronts that might be present. Simulations from the author's TEMZ model, with turbulent plasma crossing a standing conical shock in the jet, show that a mixture of turbulent and toroidal magnetic field can produce the level of polarization variability that is observed, even when the two field components are roughly equal.

Keywords

galaxies: jetsquasars: generalBL Lacertae objects: generalpolarizationshock wavesturbulence
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 10 , Issue S313: Extragalactic jets from every angle , September 2014 , pp. 122 - 127
Copyright
Copyright © International Astronomical Union 2015 

References

Abdo, A., et al. 2010, Nature, 463, 919Google Scholar
Aleksić, J., et al. 2014, A&A, 569, A46Google Scholar
Burn, B. J. 1966, MNRAS, 133, 67Google Scholar
Cawthorne, T. V. 2006, MNRAS, 367, 851Google Scholar
Cawthorne, T. V., Jorstad, S. G., & Marscher, A. P. 2013, ApJ, 772, 14Google Scholar
Clausen-Brown, E., et al. 2013, A&A, 558, A144Google Scholar
Dexter, J., McKinney, J. C., Markoff, S., & Tchekhovskoy, A. 2014, MNRAS, 440, 2185Google Scholar
Gabuzda, D. C. 2013, in The Innermost Regions of Relativistic Jets and Their Magnetic Fields, ed. Gómez, J. L., EPJ Web of Conferences, 61, 07001Google Scholar
Gabuzda, D. C., Reichstein, A. R., & O'Neill, E. L. 2014, MNRAS, 444, 172Google Scholar
Hughes, P. A., Aller, H. D., & Aller, M. F. 1989, ApJ, 341, 54Google Scholar
Jones, T. W. 1988, ApJ, 332, 678Google Scholar
Jorstad, S. G., et al. 2005, AJ, 130, 1418CrossRefGoogle Scholar
Jorstad, S. G., et al. 2007, AJ, 134, 799Google Scholar
Jorstad, S. G., et al. 2013, ApJ, 773, 147Google Scholar
Kiehlmann, S., et al. 2013, in The Innermost Regions of Relativistic Jets and Their Magnetic Fields, ed. Gómez, J. L., EPJ Web of Conferences, 61, 06003Google Scholar
Komissarov, S. S., Barkov, M. V., Vlahakis, N., & Königl, A. 2007, MNRAS, 380, 51Google Scholar
Kowal, G., de Gouveia Dal Pino, E. M., & Lazarian, A. 2012, PRL, 108, 241102Google Scholar
Laing, R. A. 1980, MNRAS, 193, 439CrossRefGoogle Scholar
Larionov, V. M., et al. 2008, A&A, 492, 389Google Scholar
Larionov, V. M., et al. 2013a, ApJ, 768, 40Google Scholar
Larionov, V. M., et al. 2013b, in The Innermost Regions of Relativistic Jets and Their Magnetic Fields, ed. Gómez, J. L., EPJ Web of Conferences, 61, 04019Google Scholar
Lyutikov, M., Pariev, V. I., & Gabuzda, D. C. 2005, MNRAS, 360, 869Google Scholar
Marscher, A. P. 2013, in The Innermost Regions of Relativistic Jets and Their Magnetic Fields, ed. Gómez, J. L., EPJ Web of Conferences, 61, 04001Google Scholar
Marscher, A. P. 2014, ApJ, 780, 87Google Scholar
Marscher, A. P., et al. 2008, Nature, 452, 966Google Scholar
Marscher, A. P., et al. 2010, ApJL, 710, L126Google Scholar
Marscher, A. P. & Jorstad, S. G. 2010, in Fermi Meets Jansky — AGN at Radio and Gamma-Rays, ed. Savolainen, T., Ros, E., Porcas, R. W., & Zensus, J. A. (Bonn: Max-Planck-Institut für Radioastronomie), 171Google Scholar
Morozova, D. A., et al. 2014, AJ, 148, 42Google Scholar
Nalewajko, K. & Begelman, M. C. 2012, MNRAS, 427, 2480Google Scholar
Narayan, R. & Piran, T. 2012, MNRAS, 420, 604Google Scholar
Polko, P., Meier, D. L., & Markoff, S. 2010, ApJ, 723, 1343CrossRefGoogle Scholar
Summerlin, E. J. & Baring, M. G. 2012, ApJ, 745, 63CrossRefGoogle Scholar
Tchekhovskoy, A., Narayan, R., & McKinney, J. C. 2011, MNRAS, 418, L79Google Scholar
Vlahakis, N. 2006, in Blazar Variability Workshop II: Entering the GLAST Era, ed. Miller, H. R.et al., ASP Conf. Ser., 350, 169Google Scholar
Zheng, H., Chen, X., & Böttcher, M. 2014, ApJ, 789, 66Google Scholar