Related papers: The X-Ray Cavity Around Hotspot E in Cygnus A: Tun…

We present new radio observations of the brighter region of the northern lobe (the Northern Middle Lobe, NML) of Centaurus A obtained at 20 cm with the Australia Telescope Compact Array. The angular resolutions are ~50 and ~130 arcsec,…

We report on the first detection of a quasi-simultaneous radio-X-ray flare of Cygnus X-1. The detection was made on 2005 April 16 with pointed observations by the Rossi X-ray Timing Explorer and the Ryle telescope, during a phase where the…

We have discovered scattered broad Balmer emission lines in the spectrum of Cygnus A, using the Keck II telescope. Broad H-alpha appears in polarized flux from components on either side of the nucleus, and to a lesser extent in the nucleus.…

Cygnus X--1 is the first Galactic source confirmed to host an accreting black hole. It has been detected across the entire electromagnetic spectrum from radio to GeV $\gamma$-rays. The source's radio through mid-infrared radiation is…

Aims: Probe the high-energy ($>$60 MeV) emission from the black hole X-ray binary system, Cygnus X-1, and investigate its origin. Methods: We analysed 7.5 yr of data by Fermi/LAT with the latest PASS8 software version. Results: We report…

We present Chandra X-ray results for the jet, nucleus, and gaseous atmosphere of NGC 315, a nearby radio galaxy whose jet kinematics are known through deep radio mapping. Diffuse X-ray synchrotron emission is detected from the jet out to 30…

Using deep Chandra ACIS observation data for Cygnus A, we report evidence of non-thermal X-ray emission from radio lobes surrounded by a rich intra-cluster medium (ICM). The diffuse X-ray emission, which are associated with the eastern and…

We present a detailed VLBI study of the spectral properties of the inner core region of the radio galaxy Cygnus A at 5 GHz, 15 GHz, 22 GHz, 43 GHz and 86 GHz. Our observations include an epoch using phase-referencing at 15 GHz and 22 GHz…

We present near-IR imaging polarimetry observations of the nucleus of Cygnus A, taken with the NICMOS camera of the HST at a wavelength of 2.0 microns.These maps reveal a highly collimated region of polarized emission straddling the nucleus…

Existing radio images of a few X-shaped radio galaxies reveal Z-symmetric morphologies in their weaker secondary lobes which cannot be naturally explained by either the galactic merger or radio-lobe backflow scenarios, the two dominant…

We present a comparison of radio observations of the archetypal powerful radio galaxy Cygnus A and 2-D numerical hydrodynamical simulations. We characterize some global trends in the observed radio properties and compare them with the…

We present a {\it ROSAT} Position Sensitive Proportional Counter (PSPC) observation of the powerful radio galaxy Cygnus-A. The X-ray emission in the {\it ROSAT} band is dominated by thermal emission from the hot intracluster medium of the…

We present Keck II adaptive optics near infrared imaging and spectroscopic observations of the central regions of the powerful radio galaxy Cygnus A. The 0.05" resolution images clearly show an unresolved nucleus between two spectacular…

The central part of the massive star-forming region Cepheus A contains several radio sources which indicate multiple outflow phenomena, yet the driving sources of the individual outflows have not been identified. We present a…

Here we present Spitzer Space Telescope imaging of Cyg A with the Infrared Array Camera, resulting in the detection of the high-energy tails or cut-offs in the synchrotron spectra for all four hotspots of this archetype radio galaxy. When…

A previous analysis of the Chandra X-ray image of the center of the cooling core cluster Abell 2597 showed two ``ghost holes'' in the X-ray emission to the west and northeast of the central radio galaxy PKS 2322-123. Previous radio…

We present H-alpha and [O III] (5007 Angstroms) images of the nebula powered by the jet of the black hole candidate and microquasar Cygnus X-1, observed with the 2.5m Isaac Newton Telescope (INT). The ring-like structure is luminous in [O…

The duty-cycle of powerful radio galaxies and quasars such as the prototype Cygnus A is poorly understood. X-ray observations of inverse-Compton scattered Cosmic Microwave Background (ICCMB) photons probe lower Lorentz-factor particles than…

We present X-ray spectra of the nucleus of the nearby radio galaxy Centaurus A from observations with the XMM-Newton EPIC CCD cameras (two exposures separated by 12 months) and the Chandra HETGS. For the first time in an FRI type galaxy, we…

We model the northern middle radio lobe of Centaurus A (NGC 5128) as a buoyant bubble of plasma deposited by an intermittently active jet. The extent of the rise of the bubble and its morphology imply that the ratio of its density to that…