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The repeating FRB source, FRB 20201124A, was found to be highly active in March and April 2021. We observed the source with the Effelsberg 100-m radio telescope at 1.36 GHz on 9 April 2021 and detected 20 bursts. A downward drift in…

High Energy Astrophysical Phenomena · Physics 2021-11-01 G. H. Hilmarsson , L. G. Spitler , R. A. Main , D. Z. Li

Polarization measurements provide strong constraints on magnetic fields in star-forming systems. While magnetic field estimates of a few kiloGauss (kG) have been obtained near the surface of low-mass protostars, there are no analogous…

Astrophysics of Galaxies · Physics 2025-07-08 A. G. Cheriyan , S. Vig , Nirupam Roy , Samir Mandal , C. Carrasco-González , A. Rodríguez-Kamenetzky , A. Pasetto

Deriving the Faraday rotation measure (RM) of quasar absorption line systems, which are tracers of high-redshift galaxies intervening background quasars, is a powerful tool for probing magnetic fields in distant galaxies. Statistically…

An 11-day monitoring campaign in late 2005 reveals clear correlation in polarization between the optical emission and the region of the intensity peak (the "pseudocore") at the upstream end of the jet in 43 GHz Very Long Baseline Array…

We present multi-frequency VLBI observations of the Compact Steep-spectrum Quasar 3C147 (0538+498) made with the VLBA at the four frequencies in the available 5 GHz band and at 8.4 GHz (still under analysis), from which we derived…

Astrophysics · Physics 2007-05-23 A. Rossetti , F. Mantovani , D. Dallacasa

We present full-polarization observations at $\lambda = 0.87$ mm (345 GHz) conducted with the Atacama Large Millimeter/submillimeter Array (ALMA) toward Messier 87 (M87) and seven other radio-loud active galactic nuclei (AGN). We determine…

Astrophysics of Galaxies · Physics 2025-07-23 Ciriaco Goddi , Douglas F. Carlos

For the first time it has become possible to compare global 3D general relativistic magnetohydrodynamic (GRMHD) jet formation simulations directly to very-long baseline interferometric multi-frequency polarization observations of the…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Avery E. Broderick , Jonathan C. McKinney

We report on high angular resolution polarimetric observations of the nearby radio galaxy M87 using the Very Long Baseline Array at 24 GHz ($\lambda=$1.3 cm) and 43 GHz ($\lambda=$7 mm) in 2017-2018. New images of the linear polarization…

Astrophysics of Galaxies · Physics 2020-06-15 E. V. Kravchenko , M. Giroletti , K. Hada , D. L. Meier , M. Nakamura , J. Park , R. C. Walker

We present results of a wideband high-resolution polarization study of Hydra A, one of the most luminous FR I radio galaxies known and amongst the most well-studied. The radio emission from this source displays extremely large Faraday…

Astrophysics of Galaxies · Physics 2023-08-14 Lerato Baidoo , Richard A. Perley , Jean Eilek , Oleg Smirnov , Valentina Vacca , Torsten Ensslin

We present Faraday rotation data for radio sources in the centers of the Abell clusters A400 and A2634. These clusters contain large (> 100 kpc), tailed radio sources, each attached to the central cD galaxy. These clusters do not have…

Astrophysics · Physics 2009-11-07 Jean A. Eilek , Frazer N. Owen

We investigate how the imprint of Faraday rotation on radio spectra can be used to determine the geometry of radio sources and the strength and structure of the surrounding magnetic fields. We model spectra of Stokes Q and U for frequencies…

Astrophysics of Galaxies · Physics 2015-05-27 D. H. F. M. Schnitzeler , J. K. Banfield , K. J. Lee

Bounds on the amplitude of a scale-invariant stochastic primordial magnetic field (PMF) can be significantly improved by measurements of the Faraday Rotation (FR) of CMB polarization. The mode-coupling correlations induced by FR make it…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-26 Levon Pogosian

We present results of long-term multi-wavelength polarization observations of the powerful blazar 3C~279 after its $\gamma$-ray flare on 2013~December 20. We followed up this flare with single-dish polarization observations using two 21-m…

Astrophysics of Galaxies · Physics 2015-11-11 Sincheol Kang , Sang-Sung Lee , Do-Young Byun

Fast Radio Bursts (FRBs) are short-timescale transients of extragalactic origin. The number of detected FRBs has grown dramatically since their serendipitous discovery from archival data. Some FRBs have also been seen to repeat. The…

High Energy Astrophysical Phenomena · Physics 2024-05-21 Pavan Uttarkar , Ryan M. Shannon , Marcus E. Lower , Pravir Kumar , Danny C. Price , A. T. Deller , K. Gourdji

We use the observed polarisation properties of a sample of 26 powerful radio galaxies and radio-loud quasars to constrain the conditions in the Faraday screens local to the sources. We adopt the cosmological redshift, low-frequency radio…

Astrophysics · Physics 2009-11-10 J. A. Goodlet , C. R. Kaiser

Faraday Rotation Measure (RM) Synthesis, as a method for analyzing multi-channel observations of polarized radio emission to investigate galactic magnetic fields structures, requires the definition of complex polarized intensity in the…

Astrophysics of Galaxies · Physics 2015-05-14 P. Frick , D. Sokoloff , R. Stepanov , R. Beck

The Galactic magnetic field is an integral constituent of the interstellar medium (ISM), and knowledge of its structure is crucial to understanding Galactic dynamics. The Rotation Measures (RM) of extragalactic (EG) sources have been the…

Astrophysics of Galaxies · Physics 2019-03-28 Anna Ordog , Rebecca A. Booth , Cameron L. Van Eck , Jo-Anne C. Brown , Thomas L. Landecker

Faraday Rotation-Conversion is the simultaneous rotation of all three Stokes polarization parameters $Q$, $U$, $V$ as an electromagnetic wave propagates through a magnetized plasma. In this regime the Faraday plasma screen is characterized…

High Energy Astrophysical Phenomena · Physics 2019-05-15 Andrei Gruzinov , Yuri Levin

We present results from the highest resolution polarization imaging survey of a complete sample of extragalactic radio sources carried out to date. Our sample consists of a statistically complete flat-spectrum subset of 32 AGNs from the…

Astrophysics · Physics 2009-11-07 Matthew L. Lister

Faraday rotation has been seen at millimeter wavelengths in several low luminosity active galactic nuclei, including Event Horizon Telescope (EHT) targets M87* and Sgr A*. The observed rotation measure (RM) probes the density, magnetic…

High Energy Astrophysical Phenomena · Physics 2020-10-07 Angelo Ricarte , Ben S. Prather , George N. Wong , Ramesh Narayan , Charles Gammie , Michael Johnson