The gigantic shells of gas are densely star-forming, and are able to keep their delicate shape due to the galaxy’s gentle gravity.
The bubbles were created during the dynamic life histories of numerous stellar generations. After high-mass stars formed in dense gas regions, they generated powerful winds that strip off surrounding matter. Finally, they exploded as supernovae, sending shock waves through the denser gas regions that heated and expanded the gas to create these fragile shells.
Three of the bubbles towards the top right of the photo are lit up by an ultraluminous X-ray source.
One possible explanation for this is an intermediate-mass black hole that could be emitting intense irradiation as it sucks in nearby material.
