Red-shifted H2O emission in NGC 3079: More evidence for a pc-scale circumnuclear torus?

Y. Hagiwara, C. Henkel, W. A. Sherwood, W. A. Baan
2002 Astronomy and Astrophysics  
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 km/s with respect to the systemic velocity of the galaxy (about 1120 km/s). Symmetrically bracketing the systemic velocity, the H2O emission covers a velocity range of 450 km/s with only one potential narrow gap (20 km/s) near the systemic velocity itself. Velocity drifts of individual components are not
more » ... 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.
doi:10.1051/0004-6361:20020508 fatcat:mtkwvtplmrbkhm6vvh6cvmzune