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The latest results of the most detailed analysis of multi-epoch polarization-sensitive observations of active galactic nuclei (AGN) jets at parsecs scales by very long baseline interferometry (VLBI) reveal several characteristic patterns of…

High Energy Astrophysical Phenomena · Physics 2024-02-13 R. V. Todorov , E. V. Kravchenko , I. N. Pashchenko , A. B. Pushkarev

Very long baseline interferometric observations of the radio galaxy 3C 120 show a systematic presence of gradients in Faraday rotation and degree of polarization across and along the jet. These are revealed by the passage of multiple…

Astrophysics · Physics 2008-07-17 J. L. Gomez , I. Agudo , A. P. Marscher , S. G. Jorstad , M. Roca-Sogorb

We present simulations of relativistic jets propagating in a nonuniform medium. Specifically, we study the bending of jets propagating obliquely to the vector of the density-gradient. Our results are applied to the NGC 4258, where such a…

Astrophysics · Physics 2008-02-03 T. Plewa , J. Ma. Marti , E. Mueller , M. Rozyczka , M. Sikora

We describe the parsec-scale kinematics of 200 AGN jets based on 15 GHz VLBA data obtained between 1994 Aug 31 and 2011 May 1. We present new VLBA 15 GHz images of these and 59 additional AGN from the MOJAVE and 2 cm Survey programs. Nearly…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-17 M. L. Lister , M. F. Aller , H. D. Aller , D. C. Homan , K. I. Kellermann , Y. Y. Kovalev , A. B. Pushkarev , J. L. Richards , E. Ros , T. Savolainen

Observational studies of collimation in jets in active galactic nuclei (AGN) are a key to understanding their formation and acceleration processes. We have performed an automated search for jet shape transitions in a sample of 367 AGN using…

We report observations of Faraday rotation measures (RMs) for a sample of 191 extragalactic radio jets observed within the MOJAVE program. Multifrequency VLBA observations were carried out over twelve epochs in 2006 at four frequencies…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-12 T. Hovatta , M. L. Lister , M. F. Aller , H. D. Aller , D. C. Homan , Y. Y. Kovalev , A. B. Pushkarev , T. Savolainen

We present an overview of new HST imaging polarimetry of six nearby radio galaxies with optical jets. These observations triple the number of extragalactic jets with subarcsecond-resolution optical polarimetry. We discuss the polarization…

Relativistic jets originating at the center of AGN are embedded in extreme environments with strong magnetic fields and high particle densities, which makes them a fundamental tool for studying the physics of magnetized plasmas. We aim to…

High Energy Astrophysical Phenomena · Physics 2025-06-04 V. Bartolini , D. Dallacasa , J. L. Gómez , M. Giroletti , R. Lico , J. D. Livingston

Motivated by recent observations that show increasing fractional linear polarization with increasing wavelength in a small number of optically thin jet features, i.e. "inverse depolarization", we present a physical model that can explain…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Daniel C. Homan

Evidence that the magnetic fields of extragalactic jets have a significant fraction of their energy in a random component is briefly summarized, and a detailed model of evolving, jet polarization structures is constructed, based on this…

Astrophysics · Physics 2009-11-10 Philip A. Hughes

In extragalactic jets, the apparent position of the bright/narrow end (the core) depends on the observing frequency, owing to synchrotron self-absorption and external absorption. The effect must be taken into account in order to achieve…

Astrophysics of Galaxies · Physics 2009-04-17 Y. Y. Kovalev , A. B. Pushkarev , A. P. Lobanov , K. V. Sokolovsky

We present Faraday Rotation Measure (RM) properties of seven active galactic nuclei (AGN), observed with the NRAO VLA at three epochs in 2012-2014. Data was taken at 1.4, 2.2, 5.0, 8.2, 15.4, 22.4, 33.5 and 43.1 GHz quasi simultaneously in…

High Energy Astrophysical Phenomena · Physics 2015-06-23 E. V. Kravchenko , W. D. Cotton , Y. Y. Kovalev

We present first-epoch, milliarcsecond-scale linear polarization images at 15 GHz of 133 jets associated with AGN in the MOJAVE survey (Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments). The sample consists of all known…

Astrophysics · Physics 2009-09-29 M. L. Lister , D. C. Homan

Rotation measure observations of 9 quasars, 4 BL Lacertae objects, and 3 radio galaxies are presented. The rest frame rotation measures in the cores of the quasars and the jets of the radio galaxy M87 are several thousand radians per meter…

Astrophysics · Physics 2008-11-26 R. T. Zavala , G. B. Taylor

Highly collimated outflows (jets) are observed across a wide range of astrophysical systems involving the accretion of material onto central objects, from supermassive black holes in active galaxies to proto-brown dwarfs and stellar-mass…

Radio polarimetric observations of Active Galactic Nuclei can reveal the magnetic field structure in the parsec-scale jets of these sources. We have observed the gamma-ray blazar 3C 273 as part of our multi-frequency survey with the Very…

High Energy Astrophysical Phenomena · Physics 2012-08-09 T. Hovatta , M. L. Lister , M. F. Aller , H. D. Aller , D. C. Homan , Y. Y. Kovalev , A. B Pushkarev , T. Savolainen

Three-dimensional magnetohydrodynamical simulations of strongly magnetized ``light'' conical jets have been performed. An investigation of the transition from sub-Alfv\'enic to super-Alfv\'enic flow has been made for nearly poloidal and for…

Astrophysics · Physics 2009-10-31 P. E. Hardee , A. Rosen

Faraday rotation is an important probe of the magnetic fields and magnetized plasma around active galactic nuclei (AGN) jets. We present a Faraday rotation measure image of the M87 jet between 85.2 GHz and 101.3 GHz with a resolution of ~2"…

In this paper we use radio polarimetric observations of the jet of the nearby bright quasar 3C\,345 to estimate the fluid velocity on kiloparsec scales. The jet is highly polarized, and surprisingly, the electric vector position angles in…

High Energy Astrophysical Phenomena · Physics 2015-06-11 David H. Roberts , John F. C. Wardle

(Abridged) We consider the polarization properties of optically thin synchrotron radiation emitted by relativistically moving electron--positron jets carrying large-scale helical magnetic fields. In our model, the jet is cylindrical, and…

Astrophysics · Physics 2009-11-10 Maxim Lyutikov , Vladimir I. Pariev , Denise C. Gabuzda