2004ApJ...612..780T

We present Very Long Baseline Array (VLBA) observations of the gigamaser galaxy TXS 2226-184 at 1.3 and 5 GHz. These observations reveal the parsec-scale radio structure of this Seyfert galaxy with exceptionally luminous water maser emission. The source is found to be extended on scales of 10-100 pc with some embedded compact sources, but it has no readily identifiable flat-spectrum active nucleus. This morphology resembles that of the nearby compact starburst galaxy Mrk 273, although no significant far-infrared emission has been detected to support the starburst scenario. The narrow (125 km/s) HI absorption in TXS 2226-184 discovered with the Very Large Array (VLA) is also detected with the VLBA. This H I absorption is distributed across the extended emission, probably cospatial with the water masers. The broad (420 km/s) line seen by the VLA is not detected, suggesting that it arises from more extended gas that is absorbing the emission beyond the central tens of parsecs.