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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

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"…

We present new 6 and 20 cm Very Large Array (VLA) observations of polarized continuum emission of roughly 0.5 square degrees of the Galactic center (GC) region. The 6 cm observations detect diffuse linearly-polarized emission throughout the…

Astrophysics of Galaxies · Physics 2015-05-27 C. J. Law , M. A. Brentjens , G. Novak

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

A Faraday rotation measure (RM) catalogue, or RM Grid, is a valuable resource for the study of cosmic magnetism. Using the second data release (DR2) from the LOFAR Two-metre Sky Survey (LoTSS), we have produced a catalogue of 2461…

We study the Faraday rotation measure (RM) variability of flat spectrum radio quasar 1633+382 on 5 epochs spanning from 2004 to 2008. We used 4 to 43~GHz VLBI polarization data from VLBA. Core RM across 4 to 15 GHz scales with a power index…

High Energy Astrophysical Phenomena · Physics 2025-05-07 Kah Chun Lai , Juan Carlos Algaba Marcos , Zamri bin Zainal Abidin

We present sensitive, high dynamic range, Very Long Baseline Array (VLBA) polarimetric observations of the cores of three powerful radio galaxies: 3C166, 3C236 and 3C390.3. Significant polarization is detected in one source (3C166) allowing…

Astrophysics · Physics 2009-11-06 G. B. Taylor , D. H. Hough , T. Venturi

We present the results of a parsec-scale polarization study of three FRI radio galaxies - 3C66B, 3C78 and 3C264 - obtained with the Very Long Baseline Array at 5, 8 and 15 GHz. Parsec-scale polarization has been detected in a large number…

Astrophysics of Galaxies · Physics 2011-02-11 P. Kharb , D. C. Gabuzda , C. P. O'Dea , P. Shastri , S. A. Baum

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

The source of Faraday rotation in the jet of the radio galaxy 3C120 is analyzed through Very Long Baseline Array observations carried out between 1999 and 2007 at 86, 43, 22, 15, 12, 8, 5, 2, and 1.7 GHz. Comparison of observations from…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 José L. Gómez , Mar Roca-Sogorb , Iván Agudo , Alan P. Marscher , Svetlana G. Jorstad

The idea that systematic Faraday Rotation gradients across the parsec-scale jets of AGNs can reveal the presence of helical magnetic (B) fields has been around since the early 1990s. These gradients are taken to be due to the systematic…

High Energy Astrophysical Phenomena · Physics 2019-08-19 Mehreen Mahmud , Colm P. Coughlan , Eoin Murphy , Denise C. Gabuzda , Redmond Hallahan

Radio quasar sightlines with strong MgII absorption lines display statistically enhanced Faraday Rotation Measures (RM) indicating the presence of additional magneto-active plasma with respect to sightlines free of such absorption. In this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 M. L. Bernet , F. Miniati , S. J. Lilly

We performed multi-frequency studies on the gigahertz-peaked spectrum high-redshift quasar 0858-279. Initially, the source presented itself in the early VLBI images as a very peculiar resolved blob. We observed the quasar with the VLBA at…

Astrophysics of Galaxies · Physics 2021-12-22 N. A. Kosogorov , Y. Y. Kovalev , M. Perucho , Yu. A. Kovalev

We present Very Long Baseline Array (VLBA) observations of the nucleus of NGC 1275, the central, dominant galaxy in the Perseus cluster of galaxies. These are the first observations to resolve the linearly polarized emission from 3C84, and…

Astrophysics · Physics 2009-09-17 G. B. Taylor , N. E. Gugliucci , A. C. Fabian , J. S. Sanders , G. Gentile , S. W. Allen

We have measured the Faraday rotation of 62 extra-galactic background sources in 58 fields using the CSIRO Australia Telescope Compact Array (ATCA) with a frequency range of 1.1 - 3.1 GHz with 2048 channels. Our sources cover a region $\sim…

Astrophysics of Galaxies · Physics 2021-02-03 J. D. Livingston , N. M. McClure-Griffiths , B. M. Gaensler , A. Seta , M. J. Alger

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 a detailed study of the Faraday depth structure of four bright (> 1 Jy), strongly polarized, unresolved, radio-loud quasars. The Australia Telescope Compact Array (ATCA) was used to observe these sources with 2 GHz of…

Magnetized plasmas traversed by linearly polarized light will reveal their presence by the frequency dependent Faraday rotation of the angle of polarization. The regions surrounding the black holes powering the jets in AGNs are expected to…

Astrophysics of Galaxies · Physics 2016-01-12 W. D. Cotton , E. Kravchenko , Y. Kovalev , E. Fomalont

Polarization observations at 21cm and 18cm towards the local Taurus molecular cloud complex were made with the Effelsberg 100-m telescope. Highly structured, frequency-dependent polarized emission features were detected. We discuss…

Astrophysics · Physics 2009-11-10 M. Wolleben , W. Reich

We determined Faraday rotation measures (RMs) towards 137 pulsars in the northern sky, using Low-Frequency Array (LOFAR) observations at 110-190 MHz. This low-frequency RM catalogue, the largest to date, improves the precision of existing…