Abstract
Astron.Astrophys. 419 (2004) 127-137 Long-slit optical emission-line spectra of the H2O megamaser galaxies ESO
103-G03, TXS 2226-184, and IC 1481 are evaluated in order to look for
characteristics typical for water-megamaser galaxies. We present rotation
curves, line ratios, electron densities, temperatures, and Hbeta luminosities.
The successful line-profile decompositions rest on d-Lorentzians with an
additional parameter d to adjust the wings, rather than Gaussians or
Lorentzians as basic functions. No significant velocity gradient is found along
the major axis in the innermost 2 kpc of TXS 2226-184. IC 1481 reveals a
spectrum suggestive of a vigorous starburst in the central kiloparsec 10^8
years ago. None of the three galaxies shows any hints for outflows nor special
features which could give clues to the presence of H2O megamaser emission. The
galaxies are of normal Seyfert-2 (ESO 103-G035) or LINER (TXS 2226-184, IC
1481) type.