1.9k citations · 15k across the 67 of their papers we have counts for
20 papers · 1 filter
Towards millimeter VLBI
T. P. Krichbaum, U. Bach, D. A. Graham +6
We discuss the present performance and the future perspectives of VLBI in the 3 mm to 0.85 mm observing bands (so called mm-VLBI). The availability of new telescopes and the recent…
Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
Sheperd Doeleman, Jonathan Weintroub, Alan E. E. Rogers +25
The cores of most galaxies are thought to harbour supermassive black holes, which power galactic nuclei by converting the gravitational energy of accreting matter into radiation (r…
6.7 GHz methanol absorption toward the Seyfert 2 galaxy NGC 3079
C. M. V. Impellizzeri, C. Henkel, A. L. Roy +1
The detection of the 6.7 GHz line of methanol (CH3OH) is reported for the first time toward an object beyond the Magellanic Clouds. Using the Effelsberg 100 m telescope, two absorp…
Phase correction of VLBI with water vapour radiometry
A. L. Roy, H. Rottmann, U. Teuber +1
We demonstrate phase correction of 3 mm VLBI observations using the scanning 18 GHz to 26 GHz water vapour radiometer at Effelsberg and we demonstrate an absolute accuracy of 15 mm…
Jet-cloud collisions in the jet of the Seyfert galaxy NGC3079
Enno Middelberg, Ivan Agudo, Alan L. Roy +1
We report the results from a six-year, multi-epoch very long baseline interferomertry monitoring of the Seyfert galaxy NGC3079. We have observed NGC3079 during eight epochs between…
Molecular tori in AGN: a search using excited states of OH
C. M. Violette Impellizzeri, Alan L. Roy, Christian Henkel
One of the fundamental concepts in the unified scheme of AGN is that both Seyfert 1 and Seyfert 2 galaxies harbour supermassive nuclear engines blocked from direct view by an optic…