activity
19992004
most citedHigher Resolution VLBI Imaging with Fast Frequency Switching

1 citations · 1 across the 5 of their papers we have counts for

collaborators

8 papers

astro-ph2004

A Multiband Approach to AGN: Radioscopy & Radio Astronomy

M. Kadler, E. Ros, J. Kerp +3

Only in the radio-loud population of active galactic nuclei (AGN) does the production, collimation, and acceleration of powerful relativistic jets take place. We introduce here a c…

astro-ph2004

VLBI detections of a source weaker than 100 mJy at 86 GHz

E. Middelberg, A. L. Roy, R. C. Walker +1

We use a new phase-calibration strategy to calibrate the phase of 86 GHz VLBI observations of the FR I radio galaxy NGC 4261. Instead of switching between a calibrator source and t…

astro-ph2003

Where has all the polarization gone?

E. Middelberg, A. L. Roy, U. Bach +2

We have observed the five radio galaxies NGC1052, NGC4261, Hydra A, Centaurus A and Cygnus A with polarimetric VLBI at 15 GHz to look for possible Faraday rotation in foreground ab…

astro-ph2003

Approaching NGC3079 with VLBI

E. Middelberg, T. P. Krichbaum, A. L. Roy +2

The Seyfert 2 galaxy NGC3079 is one of the nearest radio-weak AGN. We have carried out multi-frequency, multi-epoch VLBI observations of this object and detected new components, pr…

astro-ph20021 cited

Higher Resolution VLBI Imaging with Fast Frequency Switching

E. Middelberg, A. L. Roy, R. C. Walker +2

Millimetre-VLBI is an important tool in AGN astrophysics, but it is limited by short atmospheric coherence times and poor receiver and antenna performance. We demonstrate a new kin…

astro-ph2000

Parsec-Scale Jets and Tori in Seyfert Galaxies

A. L. Roy, J. M. Wrobel, A. S. Wilson +6

What causes the dichotomy between very powerful and very weak radio emission from AGNs? Perhaps the engines are the same but the jets get disrupted by dense ISM in radio-quiet obje…