Abstract
We report the results of our observations of the nebular complex MH9/10/11, associated with the ULX HoIX X-1, with a scanning Fabry-Pérot Interferometer. Two regions differing by their kinematics and line ratios may be distinguished, roughly corresponding to the bubble nebula MH9/10 and the fainter HII-region MH11. For MH9/10 we find an expansion rate of 20 to 70 km s-1 that is different for the approaching and receding parts. MH11 is characterised by a very low velocity dispersion (≲ 15 km s-1) and nearly constant line-of-sight velocities. The properties of MH11 may be explained by photoionization of a gas with hydrogen density of ∼ 0.2 cm-3. The luminosity required for that should be of the order of 1039 erg s-1. A source of similar power is required to explain the expansion rate of MH9/10. Modelling results also indicate that the oxygen abundance in MH11 is about solar.
