Related papers: Stratification in polarization and Faraday rotatio…
Parsec-scale multi-wavelength VLBA polarization observations can be used to study the magnetic-field structures of Active Galactic Nuclei (AGN) based on Faraday Rotation (FR) gradients. A number of transverse FR gradients have been found,…
One possible origin for polarization structures across jets of Active Galactic Nuclei (AGNs) with a central "spine" of orthogonal magnetic field and a "sheath" of longitudinal magnetic field along one or both edges of the jet is the…
We present results on the compact steep-spectrum quasar 3C 48 from observations with the VLBA, MERLIN and EVN at multiple radio frequencies. In the 1.5-GHz VLBI images, the radio jet is characterized by a series of bright knots. The active…
We present the first radio emission simulations from high resolution three dimensional relativistic hydrodynamic jets, which allow for a study of the observational implications of the interaction between the jet and external medium. This…
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…
Relatively few Very Long Baseline Interferometry (VLBI) polarization observations have been carried out at 18 cm. The importance of such observations lies in their ability to reveal information about the jet magnetic ({\bf B}) field…
Results are presented from long term VLBI monitoring of the parsec-scale radio jet in 3C120, primarily at 5 and 1.7 GHz. Numerous superluminal features are followed, some over large fractional distances from the core. The speeds of the…
We present 2.4" resolution, high sensitivity radio continuum observations of the nearby spiral galaxy NGC 4258 in total intensity and linear polarization obtained with the Very Large Array at 3.6 cm (8.44 GHz). The radio emission along the…
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…
We present results from multifrequency polarimetry of NRAO 140 using the Very Long Baseline Array. These observations allow us to reveal the distributions of both the polarization position angle and the Faraday rotation measure (RM). These…
The sensitivity, stability, and uniformity of calibration of the VLBA has revolutionized parsec-scale polarization studies of AGN jets. Not only does polarization probe the magnetic field structures of jets, serving as a hydrodynamic tracer…
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…
We present three-epoch polarimetric images of the quasar 3C 454.3 obtained with the Very Long Baseline Array at 22 and 43 GHz. 22 GHz polarized intensity images show a sudden change in the polarization structure of a bright eastern…
We investigate the structure of the kpc-scale jet in the nearby (z = 0.073) radio galaxy 3C 15, using new optical Hubble Space Telescope (HST) ACS/F606W polarimetry together with archival multi-band HST imaging, Chandra X-ray data and 8.4…
We present Very Long Baseline Array observations of the radio galaxy 3C120 at 5, 8, 12, and 15 GHz designed to study a peculiar stationary jet feature (hereafter C80) located ~80 mas from the core, which was previously shown to display a…
The Very Large Array has been used at five frequencies to study the structure and linear polarization of SS433 on scales as small as ~0.1" ~ 500 AU. Each jet consists of a sharp, curving ridge-line at the leading edge, plus significant…
We present images of the jets in the nearby radio galaxy NGC 315 made with the VLA at five frequencies between 1.365 and 5 GHz with resolutions between 1.5 and 45 arcsec FWHM. Within 15 arcsec of the nucleus, the spectral index of the jets…
3C84 (NGC1275) is one of the brightest radio sources in the mm radio-bands, which led to a plethora of VLBI observations at numerous frequencies over the years. They reveal a two-sided jet structure, with an expanding but not…
We present analysis of the flux and polarization variability of parsec scale radio jets from a dual-frequency, six-epoch, VLBA polarization experiment monitoring 12 blazars. The observations were made at 15 and 22 GHz at bimonthly intervals…
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"…