Researchers from Bengaluru institute find links to sources that heat up puffed gases swirling around Milky Way

Studies conducted a few decades ago first discovered the presence of a gaseous sphere extending to 7 lakh light years surrounding the Milky Way. It measured a few degrees Kelvin. But in more recent years, newer studies confirmed even hotter gases (10 million degrees Kelvin). But the source of such intense heat being pumped into the gases around the Milky Way had remained a mystery.

Unravelling this mystery, researchers from the RRI and their collaborators at Ohio State University and IIT-Palakkad studied the emission and absorption signals emerging from this fiery gas belt. The team found that the X-ray emitting hot gas was caused by a puffed-up region around the stellar disc of the Milky Way.

“Since there is a continuous ongoing star formation at various regions across the disk of the Milky Way, the massive stars in these regions explode as supernovae, and heat the gas around the disk to high temperatures,” added Bisht.

In addition to being extremely hot, the researchers traced the presence of alpha elements like neon and manganese in these emissions which they said revealed an entirely new phenomenon about the star formation process.

“In a few directions, this fiery gas seemed enriched with large quantities of alpha elements, such as sulphur, magnesium, neon and more. This is a vital clue of the nuclear reactions underway within the stellar core. These elements are thrown out of massive stars during supernovae explosions,” said Biman Nath, a faculty member at the RRI.

Such turbulent and hot gas eventually rises and swirls around the disc violently, before it either escapes into the surrounding medium or cools and falls back onto the disc, the team noted.