  One of the interesting features of Ultraluminous X-ray sources is that many
of them are surrounded by luminous nebulae exhibiting diverse observational
properties. In different cases the nebulae are photoionized or shock-powered.
Generally, the two energy sources appear to coexist. ULX bubble nebulae may be
considered a new class of shock-powered nebulae similar to upscaled versions of
stellar wind bubbles. Their expansion rates support constant energy influx
rather than single powerful events like Hypernova explosions.
