Noun
superbubble (plural superbubbles)
(astronomy) A very large region of space, relatively free of matter, carved out of the interstellar medium by the combination of multiple supernova bubbles resulting from supernova explosions.
These stars energize a superbubble about 1200 lys across which is observed in the visual (Hα) and X-ray portions of the spectrum. Source: Internet
Soft X-rays are emitted by hot gas (T ~ 2–3 MK) in the interior of the superbubble. Source: Internet
Within the superbubble of N44 is a smaller bubble catalogued as N44F. Source: Internet