相关论文: Milli-arcsecond scale Rotation Measure in the CSS …
Aims - We report new Very Large Array polarimetric observations of Compact Steep-Spectrum (CSS) sources at 8.4, 15, and 23GHz. Methods - Using multi-frequency VLA observations we have derived sub-arcsecond resolution images of the total…
We report here the study, in the radio band, of a sample of candidates of high Rotation Measure (RM). The point-like objects (at kpc scale) were selected by choosing unpolarised sources from the NVSS which show significant linear…
We have studied Very Long Baseline Array (VLBA) polarimetric observations of 8 sources including quasars and BL Lacs at 12, 15, 22, 24 and 43 GHz and high frequency rotation measure ($RM$) maps are presented. We find typical values for the…
Multi-frequency polarimetry with the Very Long Baseline Array (VLBA) telescope has revealed absolute Faraday Rotation Measures (RMs) in excess of 1000 rad/m/m in the central regions of 7 out of 8 strong quasars studied (e.g., 3C 273, 3C…
Multi-frequency Very Long Baseline Array (VLBA) polarimetry observation of the GHz-Peaked Spectrum (GPS) quasar OQ172 (J1445+0958) has been performed at 1.6, 2.2, 4.8, 8.3 and 15.3 GHz in 2005. Core-jet structures are detected in all bands…
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…
We completed observations with the Effelsberg 100-m radio telescope to measure the polarised emission from a complete sample of Compact Steep-Spectrum sources. We observed the sources at four different frequencies. We complemented these…
Multi-frequency (4.6, 5, 5.5, 8, 8.8, 13, 15, 22 & 43 GHz) polarization observations of 6 "blazars" were obtained on the American Very Long Baseline Array (VLBA) over a 24-hr period on 2 July 2006. Observing at several frequencies,…
Preliminary VLBA polarisation results on 6 ``blazars'' from 6.5-cm to 7-mm are presented here. Observing at several different wavelengths, separated by short and long intervals, enabled reliable information about the magnetic (B) field…
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…
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 report VLBA polarimetric observations of the CSS sources 3C119, 3C318, and 3C343 at 5 and 8.4 GHz. The CSS source 3C119 has source rest-frame RM values up to ~10200 rad/m**2 in a region which coincides with a change in the direction of…
The polarisation properties of the intrinsically small (< 20 kpc) radio sources are briefly discussed. At centimetric and decimetric wavelengths, substantial polarised emission is often detected in quasars and, at a lower level, in radio…
As radio polarised emission from astrophysical objects traverse through foreground magnetised plasma, the physical conditions along the lines of sight are encrypted in the form of Rotation Measure (RM). We performed broadband…
At a distance of 20 pc from the purported supermassive black hole powering quasars, temperatures and densities are inferred from optical observations to be ~10**4 K and ~10**4 cm**-3. Here we present Very Long Baseline Interferometry radio…
We perform polarimetry analysis of 20 active galactic nuclei (AGN) jets using the Very Long Baseline Array (VLBA) at 1.4, 1.6, 2.2, 2.4, 4.6, 5.0, 8.1, 8.4, and 15.4 GHz. The study allowed us to investigate linearly polarized properties of…
We have used the VLBA at 15 GHz to image the structure of 132 strong compact AGN and quasars with a resolution better than one milliarcsecond and a dynamic range typically exceeding 1000 to 1. These observations were made as part of a…
The NRAO VLA Sky Survey (NVSS) Rotation Measure (RM) catalogue is invaluable for the study of cosmic magnetism. However, the RM values reported in it can be affected by n$\pi$-ambiguity, resulting in deviations of the reported RM from the…
We characterised and studied, in the radio band, a sample of candidates of high Rotation Measure (RM). These point-like objects show a strong depolarisation at 21cm. This feature suggests the presence of a very dense medium surrounding them…
We present multi-frequency VLBA observations of two polarized Compact Symmetric Objects (CSOs), J0000+4054 and J1826+1831, and a polarized CSO candidate, J1915+6548. Using the wavelength-squared dependence of Faraday rotation, we obtained…