English
Related papers

Related papers: A multiband study of Hercules A. II. Multifrequenc…

200 papers

The knowledge of the physical conditions occurring in the relativistic jet of radio-loud active galactic nuclei (AGNs) is important to understand the mechanisms at the basis of their multiband emission. From parsec-scale radio observations…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-29 M. Orienti , G. Giovannini , D. Dallacasa , M. Giroletti , T. Venturi , F. D'Ammando , S. Vercellone , M. Tavani

The parsec-scale Faraday rotation measure (RM) distribution of six "blazars" is investigated using multi-frequency (4.6--43 GHz) polarization observations taken on 2006 July 2 with the VLBA. Analysis of the RM provides the direction of the…

Astrophysics · Physics 2009-02-11 Shane P. O'Sullivan , Denise C. Gabuzda

The FRI/FRII dichotomy is a much debated issue in the astrophysics of extragalactic radio sources. Study of the properties of HYbrid MOrphology Radio Sources (HYMORS) may bring crucial information and lead to a step forward in understanding…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Maciej Ceglowski , Marcin Gawronski , Magdalena Kunert-Bajraszewska

Deep radio observations at 5 and 8 GHz are presented of a complete sample of 11 radio galaxies with redshifts 0.85 < z < 1.5, selected from the 6C sample of Eales. The radio data, taken using the VLA in A, B and C array configurations,…

Astrophysics · Physics 2015-06-24 P. N. Best , S. A. Eales , S. Rawlings , H. J. A. R"ottgering , M. S. Longair

The goal of this work is a detailed study of the nearby, low power radio galaxy B2 1144+35B. For this purpose, we performed new Very Long Baseline Array (VLBA) and Very Large Array (VLA) observations. This source has several properties…

Astrophysics · Physics 2009-11-13 G. Giovannini , M. Giroletti , G. B. Taylor

We present results from imaging of the radio filaments in the southern giant lobe of Centaurus A using data from GMRT observations at 325 and 235 MHz, and outcomes from filament modelling. The observations reveal a rich filamentary…

This is a paper on young jet material in a frustratingly complex environment. NGC 1052 has a compact, flat- or GHz-peaked-spectrum radio nucleus consisting of bi-symmetric jets, oriented close to the plane of the sky. Many features on both…

We present 74 MHz and 330 MHz VLA observations of Abell 754. Diffuse, halo-like emission is detected from the center of the cluster at both frequencies. At 330 MHz the resolution of 90'' distinguishes this extended emission from previously…

Astrophysics · Physics 2009-11-06 N. E. Kassim , T. E. Clarke , T. A. Enßlin , A. S. Cohen , D. M. Neumann

HST images of the western hot spot of the nearby FRII radio galaxy Pictor A resolve the hot spot into an amorphous region of highly polarized wisps. The high polarization (>~ 50%) indicates that the optical emission is synchrotron radiation…

Astrophysics · Physics 2016-08-30 R. C. Thomson , P. Crane , C. D. Mackay

We present a comprehensive multifrequency VLBI analysis of the FRII, high-excitation radio galaxy 3C 452, aiming to resolve and analyze for the first time its twin-jet structure on sub-parsec scales. Our data set comprises High Sensitivity…

High Energy Astrophysical Phenomena · Physics 2026-05-06 Eftychia Madika , Bia Boccardi , Luca Ricci , Paola Grandi , Eleonora Torresi , Gabriele Giovannini , Matthias Kadler , J. Anton Zensus

Radio galaxies are linearly polarized -- an important property that allows us to infer the properties of the magnetic field of the source and its environment. However at low frequencies, Faraday rotation substantially depolarizes the…

We present results from 1.4 and 5 GHz observations at matched resolution with the Karl G. Jansky Very Large Array (VLA) of 11 powerful 3C FR II quasars. We examine the 11 quasars along with a sample of 13 narrow-line FR II radio galaxies…

Astrophysics of Galaxies · Physics 2019-01-09 S. Vaddi , P. Kharb , R. A. Daly , C. P. O'Dea , S. A. Baum , D. K. Deo , T. C. Barbusca , C. Murali

We report on first results of an ongoing effort to image a small sample of high-redshift radio galaxies (HzRGs) with milliarcsecond (mas) resolution, using very-long-baseline interferometry (VLBI) techniques. Here, we present 1.7 and 5.0…

Astrophysics · Physics 2009-11-11 Miguel A. Perez-Torres , Carlos De Breuck , Wil van Breugel , George Miley

We aim to unveil their 3-dimensional geometry of Abell 2255 through WSRT observations at 18, 21, 25, 85, and 200 cm. The polarization images of the cluster were processed through rotation measure (RM) synthesis, producing three final RM…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 R. F. Pizzo , A. G. de Bruyn , G. Bernardi , M. A. Brentjens

Context. Abell 1213, a low-richness galaxy system, is known to host an anomalous radio halo detected in data of the VLA. It is an outlier with regard to the relation between the radio halo power and the X-ray luminosity of the parent…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 W. Boschin , M. Girardi , S. De Grandi , G. Riva , L. Feretti , G. Giovannini , F. Govoni , V. Vacca

The relation between giant radio halos and mini-halos in galaxy clusters is not understood. The former are usually associated with merging clusters, the latter are found in relaxed systems. In the last years, the advent of low-frequency…

The triple radio source detected in association with the luminous infrared source IRAS 16547-4247 has previously been studied with high angular resolution and high sensitivity with the Very Large Array (VLA) at 3.6-cm wavelength. In this…

Investigating the magnetic field structure in the innermost regions of relativistic jets is fundamental to shed light on the crucial physical processes giving rise to the jet formation, as well as to its extraordinary radiation output up to…

The VLBA and the VLA have been used to image the continuum radio emission from Mrk 231, a Seyfert 1 galaxy and the brightest infrared galaxy in the local universe. The smallest scales reveal a double source less than 2 pc in extent. The…

Astrophysics · Physics 2009-10-31 J. S. Ulvestad , J. M. Wrobel , C. L. Carilli

Determining the energy spectrum of an electron population can give key insights into the underlying physics of a radio source; however, the lack of high resolution, broad-bandwidth observations has left many ambiguities in our understanding…

Astrophysics of Galaxies · Physics 2014-05-01 J. J. Harwood , M. J. Hardcastle , J. H. Croston , A. Stroe , R. Morganti , E. Orru
‹ Prev 1 4 5 6 7 8 10 Next ›