Ultraluminous X-ray Sources and Their Nebulae

TL;DR

This paper reviews the properties of nebulae around ultraluminous X-ray sources, highlighting their diverse ionization mechanisms and the evidence for continuous energy input shaping their expansion.

Contribution

It introduces ULX bubble nebulae as a new class of shock-powered nebulae with evidence for ongoing energy supply, expanding understanding of ULX environments.

Findings

ULX nebulae exhibit diverse ionization properties.

Expansion rates suggest continuous energy input.

ULX bubble nebulae are akin to scaled stellar wind bubbles.

Abstract

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.