NASA | Fermi discovers giant gamma-ray bubbles in the Milky Way

Scientists have discovered a massive, mysterious structure in our Galaxy, resembling a pair of bubbles extending above and below the Galaxy center. These gamma ray emitting lobes, each 25,000 light years tall, were revealed through data processing. The structure is a few million years old, and the source of the energetic electrons within it remains unknown. Theories suggest the bubbles could be remnants of star formation or eruptions from the supermassive black hole at the Galaxy's center. Further research is needed to understand this phenomenon and its implications for the Milky Way.

What are the two hypotheses regarding the formation of the bubbles?

How might understanding this structure improve our knowledge of the Milky Way?