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Related papers: Parsec-Scale Circular Polarization Observations of…

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We present full polarization Very Long Baseline Array (VLBA) observations at 5 GHz and 15 GHz of 24 compact active galactic nuclei (AGN). These sources were observed as part of a pilot project to demonstrate the feasibility of conducting a…

This study investigates polarimetric characteristics of the blazar 3C~454.3 at 22-129~GHz using decadal~(2011-2022) data sets. In addition, we also delve into the origin of the polarization flare observed in 2019. The data sets were…

In this work we present a polarization analysis at radio frequencies of Markarian 421, one of the closest (z=0.03) TeV blazars. The observations were obtained, both in total and in polarized intensity, with the Very Long Baseline Array…

We report results from a deep polarization imaging of the nearby radio galaxy 3C$\,$84 (NGC$\,$1275). The source was observed with the Global Millimeter VLBI Array (GMVA) at 86$\,$GHz at an ultra-high angular resolution of $50\mu$as…

We interpret the linear polarization structures observed in extragalactic radio sources, even those oriented at oblique angles to the jet flows, to be due to oblique, relativistic shock fronts in the emitting regions. Many sources exhibit…

Astrophysics · Physics 2007-05-23 H. D. Aller , M. F. Aller , P. A. Hughes

We analyse the circular polarisation data accumulated in the first 7 years of the POLAMI project introduced in an accompanying paper (Agudo et al.). In the 3mm wavelength band, we acquired more than 2600 observations, and all but one of our…

Using stacking of images obtained at different epochs, we studied the variability properties of linear polarization of active galactic nucleus (AGN) jets on parsec-scales. Our sample is drawn from the MOJAVE programme, and consists of 436…

High Energy Astrophysical Phenomena · Physics 2023-06-16 D. I. Zobnina , H. D. Aller , M. F. Aller , D. C. Homan , Y. Y. Kovalev , M. L. Lister , I. N. Pashchenko , A. B. Pushkarev , T. Savolainen

Previous research showed most BL Lac objects and some quasars have aligned VLBI-core and optical polarizations, although some of the AGNs also showed no obvious relationship between VLBI-core and optical polarization angles. This may…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 J. C. Algaba , D. C. Gabuzda , P. S. Smith

Short millimeter observations of radio-loud AGN offer the opportunity to study the physics of their inner relativistic jets, from where the bulk millimeter emission is radiated. Millimeter jets are significantly less affected by Faraday…

Astrophysics of Galaxies · Physics 2014-07-02 I. Agudo , C. Thum , J. L. Gomez , H. Wiesemeyer

Although the continua of radio-loud Active Galactic Nuclei (AGN) are typically dominated by synchrotron radiation over virtually the entire spectrum, it is not clear whether the radio and higher-frequency emission originate in the same or…

Astrophysics of Galaxies · Physics 2009-02-06 J. C. Algaba , D. C. Gabuzda , P. S. Smith

Radio polarimetry is an invaluable tool to investigate the physical conditions and variability processes in active galactic nuclei (AGN) jets. However, detecting their linear and circular polarization properties is a challenging endeavor…

High Energy Astrophysical Phenomena · Physics 2016-11-30 Ioannis Myserlis , Emmanouil Angelakis , Alex Kraus , Lars Fuhrmann , Vassilis Karamanavis , J. Anton Zensus

We conducted a Very Large Array survey of eleven low luminosity active galactic nuclei for linear and circular polarization at 8.4 GHz. We detected circular polarization in one source (M81*) and linear polarization in 3 sources. Sensitivity…

Astrophysics · Physics 2009-11-07 Geoffrey C. Bower , Heino Falcke , Richard R. Mellon

We have studied the linear polarization of 86 active galactic nuclei (AGN) in the observed frequency range 80-267 GHz (3.7-1.1mm in wavelength), corresponding to rest-frame frequencies 82-738 GHz, with the IRAM Plateau de Bure…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. Trippe , R. Neri , M. Krips , A. Castro-Carrizo , M. Bremer , V. Pietu , A. L. Fontana

We present 5321 milliarcsecond-resolution total intensity and linear polarization maps of 437 active galactic nuclei (AGNs) obtained with the VLBA at 15 GHz as part of the MOJAVE survey, and also from the NRAO data archive. The former is a…

Astrophysics of Galaxies · Physics 2018-01-18 M. L. Lister , M. F. Aller , H. D. Aller , M. A. Hodge , D. C. Homan , Y. Y. Kovalev , A. B. Pushkarev , T. Savolainen

The magnetic field morphology of relativistic jets can be studied with circular polarization (CP). Recent 3D relativistic magnetohydrodynamic (RMHD) simulations coupled with radiative transfer calculations make strong predictions about the…

Astrophysics of Galaxies · Physics 2025-05-07 Joana A Kramer , Hendrik Müller , Jan Röder , Eduardo Ros

We discuss the constraints that recent observations place on circular polarization in AGN. In many sources the circular polarization is variable on short timescales, indicating that it originates in compact regions of the sources. The best…

Astrophysics · Physics 2007-05-23 J. -P. Macquart

We have compared the parsec-scale jet linear polarization properties of the Fermi LAT-detected and non-detected sources in the complete flux-density-limited (MOJAVE-1) sample of highly beamed AGN. Of the 123 MOJAVE sources, 30 were detected…

High Energy Astrophysical Phenomena · Physics 2010-08-23 T. Hovatta , M. L. Lister , Y. Y. Kovalev , A. B. Pushkarev , T. Savolainen

We report on multi-frequency polarimetry Very Long Baseline Interferometry observations of active galactic nuclei using the VLBA. These observations are used to construct images of the Faraday Rotation Measure (RM) in J1613+342, Mrk 501, 3C…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 G. B. Taylor , R. Zavala

Previously, a multi-wavelength (2cm, 4cm and 6cm) polarization study by Gabuzda, Murray and Cronin (2004) showed systematic Faraday Rotation gradients across the parsec-scale jets of several BL Lac objects, interpreted as evidence for…

Astrophysics · Physics 2007-08-03 Mehreen Mahmud , Denise Gabuzda

We are using "broadband" (4.6 to 43 GHz) multi-frequency VLBA polarization observations of compact AGN to investigate the 3-D structure of their jet magnetic (B) fields. Observing at several frequencies, separated by short and long…

Astrophysics · Physics 2008-02-01 Shane P. O'Sullivan , Denise C. Gabuzda