Related papers: A multiband study of Hercules A. II. Multifrequenc…
We present high-quality VLA images of the FR I radio galaxy 3C 31 in the frequency range 1365 to 8440 MHz with angular resolutions from 0.25 to 40 arcsec. Our new images reveal complex, well resolved filamentary substructure in the radio…
The radio lobes of the radio galaxy Hercules A contain intriguing ring-like structures concentric with the jet axis. To investigate the occurrence of such features, we have used hydrodynamic simulations of jets with a range of Mach numbers…
The prominent radio source Hercules A features complex structures in its radio lobes. Although it is one of the most comprehensively studied sources in the radio sky, the origin of the ring structures in the Hercules A radio lobes remains…
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…
Extragalactic jets are generated as bipolar outflows at the nuclei of active galaxies. Depending on their morphology, they are classified as Fanaroff-Riley type I (centre-brightened) and Fanaroff-Riley type II (edge-brightened) radio jets.…
We investigate the X-ray properties of the powerful radio galaxy Hercules A (3C 348) using ROSAT HRI, PSPC and ASCA observations. The ASCA data are well fit by a thermal plasma model with a temperature of about 4.3 keV and abundances 0.4…
We present new, low-frequency images of the powerful FR I radio galaxy Hydra A (3C 218). Images were made with the Very Large Array (VLA) at frequencies of 1415, 330, and 74 MHz, with resolutions on the order of 20". The morphology of the…
We present the results of a polarimetric study from our new high-sensitivity L-band (0.8--1.7 GHz) observation of Pictor A with the MeerKAT radio telescope. We confirm the presence of the radio jet extending from the nucleus to the western…
We employed the Very Large Array (VLA) of the National Radio Astronomy Observatory in C configuration to map 39 ultraluminous IRAS galaxies at 6~cm and 20~cm, at resolutions of ~ 4" and 15", respectively, and 24 sources at 6~cm with in the…
In this paper we present multifrequency VLA observations of the giant radio galaxy 3C 449, obtained with high sensitivity and resolution in total intensity and polarized flux. These images show the source morphology in great detail, in…
Studying the interaction between AGN jets and lobes and their surrounding environment is important in order to understand how they transfer energy to their environment as well as determining the intrinsic physical properties of the sources…
We observed 17 nearby low luminosity FR I radio galaxies using the NRAO Very Long Baseline Array (VLBA) at 1.67 GHz, as part of a multi-wavelength study of a complete sample of 21 sources selected by radio flux density from the Uppsala…
We present results from deep, wideband, high spatial and spectral resolution observations of the nearby luminous radio galaxy Cygnus A with the Jansky Very Large Array. The high surface brightness of this source enables detailed…
Global VLBI observations at 5 GHz have been performed to study the source morphology in 10 compact steep-spectrum (CSS) sources selected from the Peacock & Wall catalogue with the aim of finding asymmetric structures produced by the…
We report on a spectral study at radio frequencies of the giant radio halo in A2142 (z=0.0909), which we performed to explore its nature and origin. A2142 is not a major merger and the presence of a giant radio halo is somewhat surprising.…
We have discovered that the radio nebula surrounding the Vela pulsar covers a much wider extent than previously reported, with two lobes to the North and South of the pulsar. Indications of this object have been reported previously, but its…
We present U, V, and I-band images of the host galaxy of Hercules A (3C 348) obtained with HST/WFC3/UVIS. We find a network of dusty filaments which are more complex and extended than seen in earlier HST observations. The filaments are…
We present the results of the first successful observations of the Pie Town link with the Very Large Array (VLA) at 74 MHz on Hercules A. The improvement in resolution from 25 arcsec to 10 arcsec resolves the helical- and ring-like features…
Our recent VLBI observations of the prominent FR II radio galaxy Cygnus A with the EVN and the VLBA reveal a pronounced two-sided jet structure. At 5 GHz, we now have 4 epochs from 1986, 1991 (Carilli et al., 1991 & 1994), 1996 and 2002…
We have made ROSAT PSPC and HRI X-ray observations to study the intracluster gas surrounding the powerful radio source Hercules A. The cluster is luminous in X-rays (L_bol = 4.8x10^37 W), and the host of the radio source is the central…