Volume 387, Number 2, May IV 2002
|Page(s)||L29 - L32|
|Published online||13 May 2002|
Letter to the Editor
Red-shifted H2O emission in NGC 3079: More evidence for a pc-scale circumnuclear torus? *
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
2 Westerbork Observatory, PO Box 2, 7990 AA Dwingeloo, The Netherlands
Y. Hagiwara, Dwingeloo
Accepted: 2 April 2002
Using the Effelsberg 100-m telescope, sensitive measurements of the H2O megamaser in NGC 3079 are presented. During 2000–2001, “high velocity” features are seen that are red-shifted up to 225 with respect to the systemic velocity of the galaxy (VLSR ~ 1120 ). Symmetrically bracketing the systemic velocity, the H2O emission covers a velocity range of ~450 with only one potential narrow gap (~20 ) near the systemic velocity itself. Velocity drifts of individual components are not convincingly detected. It is shown that the presence of red-shifted emission and the absence of detectable velocity drifts are not inconsistent with the existence of a rotating circumnuclear maser disk at the very center of the galaxy. Significant differences in the overall line profile compared to NGC 4258 and a complex morphology of the radio continuum leave, however, space for scepticism.
Key words: galaxies: active / galaxies: individual: NGC 3079 / galaxies: ISM / galaxies: nuclei / radio lines: galaxies
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.